add docstring support for modules and functions (both user written and builtin).  add doc strings for `__builtin__` and `imp` modules.

This will prevent tests from dirtying the source/build directories,
or worse overwriting/removing files we care about.

This commit expands on some existing hacks, which I don't like, but
they should hopefully be going away soon.

add cpython buffer + sqlite3 module, and a couple tests.

Implement further changes required for virtualenv

don't assert() if python errors inside of a CFGVisitor's RAII scope

INSTALLING.md: add instructions on getting gdb pretty-printers to work

- make sure that, except for a few special cases, any type which
  has instance attributes gets a __dict__ descriptor
- remove instance attributes from generator and builtin_function_or_method
  objects

- oldstyle classes get a __dict__
- object().__hash__()
- old style classes __getattribute__
- str.splitlines()
- and file(unicode, unicode)
- start_new_thread takes a third argument
- set.union
- instancemethod __getattr__

Fixing makefile link

fixing makefile link

Implement set comprehensions, fix dict comprehension scope

Document that we need libssl-dev

We were already doing this for CAPI classes.
Only slightly trickier due to bootstrapping issues.

object.__reduce__, __reduce_ex__, and some friends