Update to the newest buildout.

On a new branch since tests fail.
Passing -t to bootstrap, needed until 2.0 final

Also removed 2.5 support (2.0 buildout doesn't support it)
Making buildout's executable option available

Apparently buildout used to pass it along pre-2.0. Well, in any case we can just grab it ourselves from buildout's options.
Fixed test setup to match buildout's signature
Using [test] extras_require; fixed omMelette typo
Added coverage report to nose test results.
Removed tests for different python versions.

These tests really only tested zc.buildout's internal script generation, which
supported different python versions. It wasn't djangorecipe functionality.

Buildout 2.0 removed the support for different versions, btw.
Using sys.executable instead of the same one passed by buildout.

Buildout 2.0 doesn't pass the executable anymore as it only supports a single
python executable.
Updated documentation for removal of different-python-versions support
Revert "Update to the newest buildout."

This reverts commit c7f2fece036403738c11fe1c61e5a3302f96de2b.

Needed to get the branch in shape for inclusion with master.
We'll hold back on using the latest buildout 2.0 bootstrap until
2.0 final is out.
Revert "Passing -t to bootstrap, needed until 2.0 final"

This reverts commit b759c25c5b2ad861cbe07f18e6f814639ce54cce.

Another pre-buildout2-final revert
Re-added 'python' and 'executable' keys to the mock buildout part
to better mimick buildout's behavior.
The 'python' part is required on pre-2.0 buildouts.
Added makefile and buildout cfg for buildout1+2 testing
Actually using the makefile to get buildout2 to be used
Nicer test method name
Merge pull request #62 from rvanlaar/buildout2

Buildout 2.0 support