[FYI] Rename branches: 'maint' -> 'minor'

[Stefano Lattarini]

Now that Automake 1.14 has been released, I've merged 'maint'
into 'micro', and created a new branch named 'minor' from there.
So, at this point:

 - The 'micro' branch is the one from which the next bug-fixing
   release (1.14.1) will be cut.

 - The 'micro' branch is the one from which the next minor
   release (1.15) will be cut.

 - The 'master' branch remains the one from which the next
   major release (2.0) will be cut.

Regards,
  Stefano