Readme and doc clarification about local git repos
make the doc/vundle.txt the same as README.md
Merge pull request #319 from grantbow/master

make the doc/vundle.txt the same as README.md
Bundler link update
Added support for specifying branches using full colon.  eg:  Bundle 'svermeulen/vundle.git:nameOfBranch'
Added ability to specify branch using syntax Bundle '[git url:branch]'