Renamed bootstrap.py's --version into --buildout-version

I don't think many people use this option as it isn't documented.
It used to be handy around the time when we had lots of breakage.
Nowadays it isn't needed.
So... I'm moving it out of the way to make room for --version as a proper version-returning option.

CHANGES.rst

@@ -29,6 +29,10 @@ Unreleased
   higher for this functionality.
   [lrowe]
 
+- The bootstrap script now uses ``--buildout-version`` instead of
+  ``--version`` to pick a specific buildout version.
+  [reinout]
+
 - Updated buildout's `travis-ci <https://travis-ci.org/buildout/buildout>`_
   configuration so that tests run much quicker so that buildout is easier and
   quicker to develop.

bootstrap/bootstrap.py

@@ -40,8 +40,7 @@ this script from going over the network.
 '''
 
 parser = OptionParser(usage=usage)
-parser.add_option("-v",
-                  "--version",
+parser.add_option("--buildout-version",
                   help="Use a specific zc.buildout version")
 parser.add_option("-t", "--accept-buildout-test-releases",
                   dest='accept_buildout_test_releases',
@@ -139,7 +138,7 @@ if find_links:
     cmd.extend(['-f', find_links])
 
 requirement = 'zc.buildout'
-version = options.version
+version = options.buildout_version
 if version is None and not options.accept_buildout_test_releases:
     # Figure out the most recent final version of zc.buildout.
     import setuptools.package_index

src/zc/buildout/bootstrap.txt

@@ -59,14 +59,14 @@ By default it gets the latest version:
       '/sample/eggs/zc.buildout-22.0.0...egg',
       ]...
 
-Now trying the `--version` option, that let you define a version for
+Now trying the `--buildout-version` option, that let you define a version for
 `zc.buildout`.
 
 Let's try with an unknown version::
 
     >>> print_('X'); print_(system(
     ...     zc.buildout.easy_install._safe_arg(sys.executable)+' '+
-    ...     'bootstrap.py --version UNKNOWN')); print_('X') # doctest: +ELLIPSIS
+    ...     'bootstrap.py --buildout-version UNKNOWN')); print_('X') # doctest: +ELLIPSIS
     ...
     X
     ...
@@ -77,7 +77,7 @@ Now let's try with `2.0.0`, which happens to exist::
 
     >>> print_('X'); print_(system(
     ...     zc.buildout.easy_install._safe_arg(sys.executable)+' '+
-    ...     'bootstrap.py --version 2.0.0')); print_('X')
+    ...     'bootstrap.py --buildout-version 2.0.0')); print_('X')
     ... # doctest: +ELLIPSIS
     X...Generated script '/sample/bin/buildout'...X
 
@@ -115,7 +115,7 @@ which happens to exist::
 
     >>> print_('X'); print_(system(
     ...     zc.buildout.easy_install._safe_arg(sys.executable)+' '+
-    ...     'bootstrap.py --setuptools-version 8.0 --version 2.0.0')); print_('X')
+    ...     'bootstrap.py --setuptools-version 8.0 --buildout-version 2.0.0')); print_('X')
     ... # doctest: +ELLIPSIS
     X...Generated script '/sample/bin/buildout'...X
 
@@ -145,7 +145,7 @@ specify the setuptools version, and to reuse the setuptools zipfile.
 
     >>> print_('X'); print_(system(
     ...     zc.buildout.easy_install._safe_arg(sys.executable)+' '+
-    ...     'bootstrap.py --setuptools-version 14.3 --version 2.0.0 '+
+    ...     'bootstrap.py --setuptools-version 14.3 --buildout-version 2.0.0 '+
     ...     '--setuptools-to-dir .')); print_('X')
     ... # doctest: +ELLIPSIS
     X...Using local ez_setup.py...Generated script '/sample/bin/buildout'...X