v0.13.0 - Removed & deprecated (dormant) macports support, deprecated…

… vars in favour of dep parameters, and cleaned up some core deps.

This was done in v0.12.9, but there were two bugs and the minor version number should have been bumped.
  - I broke the 'git' dep by incorrectly using a parameter
  - Removing the :macports choice broke deps that included it

Not my best work. Let's just pretend v0.12.9 never happened.

lib/babushka.rb

@@ -1,5 +1,5 @@
 module Babushka
-  VERSION        = '0.12.9'
+  VERSION        = '0.13.0'
   WorkingPrefix  = '~/.babushka'
   SourcePrefix   = '~/.babushka/sources'
   BuildPrefix    = '~/.babushka/build'