Change refspec used to fetch all branches and tags

When the repository references are sha1s the fetch command used will
not work.  This will ensure that all of the objects are still fetched,
and all of the local cache references for branches and tags will be
updated rather than just the specified reference in use.

Change-Id: Iad2554b3087a5da37dac6e9f6a72432d49fce83d
Closes-Bug: #1301435
Merge "Change refspec used to fetch all branches and tags"