Add zlc.rcp
Improve support for shallow clones using git

The current algorithm is
1) If the protocol used is not http (file, ssh, git) clone is supported
2) Otherwise check if repo belongs to know smart host, if so assume
   shallow clone is supported
3) If none of the above work, make a HEAD request and parse response
   headers to determine the host is smart explained (here)[http://stackoverflow.com/questions/9270488/]
Add tests for git shallow clones functionality
Add migemo.rcp and helm-migemo.rcp
Fix some typos and style issues
merge in some new recipes

Merge remote-tracking branches 'upstream/pr/1919' and 'upstream/pr/1922'