jayway/maven-android-plugin — pull request #259 by pa314159 (2013-12-20 14:46:25+00:00)
Title: config handler improvments

Back wih ConfigHandler improvements, rebasing resulted in a mess, so I chery-picked changes into this new branch

- can specify empty string as defaultValue
- can use expressions in defaultValue
- skip proguard if the configuration doesn't exist