bower/bower — pull request #1241 by geigerzaehler (2014-04-13 16:14:30+00:00)
Title: Use promise interface for commands

This commit changes the interface of the command functions exported by the files in `lib/commands`. The functions now return a promise and accept a logger as the first argument. This has several advantages.

* The promise style is consistent with the rest of the code.
* It removes a lot of duplicate code.
* The command factory does not need to proxy the logger object.

Follow up to #1134 and #1232.