Tweaked error messages in '_spawn_posix()'.

RT library.

Fixed 'make_release_tree()' to copy files if 'os.link()' doesn't exist.

command wasn't found or failed.  (Code supplied by Thomas Heller
<thomas.heller@ion-tof.com>.)

before storing or using.

the 'missing' parameter.

Added 'link_static_lib()' method, and 'archiver' and 'archiver_options'
  class attributes to support it.
Added 'link_executable()' method, and 'ld_exec' instance attribute
  to support it.
'newer_group()' is now able to handle missing files, so we don't have
  to kludge it by catching OSError when calling it.
'object_filenames()' and 'shared_object_filename()' now take 'keep_dir'
  flag parameters.
'library_filename()' and 'shared_library_filename()' now respect
  a directory component in the library name.
Various comment updates/deletions.

Added 'link_executable()' signature.

Added 'nuke_release_tree()' method to blow away the directory from
  which the archive file(s) are created, and call it (conditionally)
  from 'make_distribution()'.
Added 'keep_tree' option (false by default) to disable the call to
  'nuke_release_tree()'.

  install) the setup script itself.
Fixed 'build_module()' so we do *not* preserve file mode (which means
  we can install read-only files, which makes the next installation
  of this distribution fail -- at least under Unix); added a comment
  explaining this.

  call CCompiler method 'compile()' with 'include_dirs' not 'includes'.
Fixed stupid typo in 'get_source_files()'.

  consistency with 'build_ext' command option.
Changed 'compile()' and 'link_shared_object()' so 'include_dirs',
  'libraries', and 'library_dirs' can be lists or tuples.

  'generate_help()', 'wrap_text()' functions, and a little tiny test
  of 'wrap_text()'.
Changed how caller states that one option is the boolean opposite of
  another: added 'negative_opt' parameter to 'fancy_getopt()', and changed
  to use it instead of parsing long option name.

  want no output.  Still no option for a happy medium though.
Added "--help" global option.
Changed 'parse_command_line()' to recognize help options (both for the
  whole distribution and per-command), and to distinguish "regular run"
  and "user asked for help" by returning false in the latter case.
Also in 'parse_command_line()', detect invalid command name on command
  line by catching DistutilsModuleError.
  a 'negative_opt' class attribute right after 'global_options'; changed
  how we call 'fancy_getopt()' accordingly.
Initialize 'maintainer' and 'maintainer_email' attributes to Distribution
  to avoid AttributeError when 'author' and 'author_email' not defined.
Initialize 'help' attribute in Command constructor (to avoid
  AttributeError when user *doesn't* ask for help).
In 'setup()':
  * show usage message before dying when we catch DistutilsArgError
  * only run commands if 'parse_command_line()' returned true (that
    way, we exit immediately when a help option is found)
  * catch KeyboardInterrupt and IOError from running commands
Bulked up usage message to show --help options.
Comment, docstring, and error message tweaks.

Bunch of little bug fixes that appeared in building non-packagized
distributions.  Mainly:
  - brain-slip typo in 'get_package_dir()'
  - don't try to os.path.join() an empty path tuple -- it doesn't like it
  - more type-safety in 'build_module()'

Now supports the full range of intended formats (tar, ztar, gztar, zip).
"-f" no longer a short option for "--formats" -- conflicts with new
  global option "--force"!

on the manifest file syntax.

  global options table.
Every Command instance now has its own copies of the global options,
  which automatically fallback to the Distribution instance.  Changes:
  - initialize them in constructor
  - added '__getattr__()' to handle the fallback logic
  - changed every 'self.distribution.{verbose,dry_run}' in Command to
    'self.{verbose,dry_run}'.
  - filesystem utility methods ('copy_file()' et al) don't take 'update'
    parameter anymore -- instead we pass 'not force' to the underlying
    function as 'update'
Changed parsing of command line so that global options apply to all
  commands as well -- that's how (eg.) Command.verbose will be initialized.
Simplified 'make_file()' to use 'newer_group()' (from util module).
Deleted some cruft.
Some docstring tweaks.

  the code a bit and should make it work under Windows even with trailing
  backslash.
Fixed a couple of docstrings.
Added comment about 'make_file()' possibly being redundant and unnecessary.

-q/--quiet reasonably elegantly.

  - change how we call it
  - added methods 'library_dir_option()', 'library_option()', and
    'find_library_file()' that it calls
Added 'force' flag; it's automatically "respected", because this class
  always rebuilds everything!  (Which it to say, "force=0" is not respected.)

Catch up with changes in 'gen_lib_options()':
  - change how we call it
  - added methods 'library_dir_option()', 'library_option()', and
    'find_library_file()' that it calls
Added 'force' flag and changed compile/link methods to respect it.

  has a directory component, then we only search for the library in
  that one directory, ie. ignore the 'library_dirs' lists for that
  one library.
Changed calling convention to 'gen_lib_options()' again: now, it takes
  a CCompiler instance and calls methods on it instead of taking
  format strings.  Also implemented the new "library name" semantics
  using the 'find_library_file()' method in the CCompiler instance.
Added 'force' flag to CCompiler; added to constructor and 'new_compiler()'.
Added 'warn()' method.