Indent code for majver == 3 and minver >= 4 and add '_collections_abc' as
required module, needed as of Python 3.4.0a4
document that --extra-search-dir is working again
have the metavar be singular to match the option
Merge pull request #489 from msabramo/fix_python34a4

Indent code for majver == 3 and minver >= 4 and add '_collections_abc' as  required module, needed as of Python 3.4.0a4