Smarter gitignore.
Adds VCS urls support.

Now, requirements, containing VCS urls could be
compiled. During compilation, pip-compile will checkout
sources, get all dependencies and pin spec to exact
repository revision.
Configurable via PIPTOOLS_ROOT environment variable, default is ~/.pip-tools. And attempt to make pip-compile-detailed.t results more stable.
Merge branch 'work-with-vcs' into my-future
Fixed issue with packages with non-standart .egg-info placement.
Fixed issue with requirement inheritance when files are in the subdirectory.
Fixed issue when *.egg-info directory is in unusual place.
Merge branch 'my-future' of github.com:svetlyak40wt/pip-tools into my-future
Merge branch 'my-future' of git://github.com/svetlyak40wt/pip-tools into my-future

Conflicts:
	piptools/package_manager.py