Improvements and cleanup for 0.7-SNAPSHOT

  * Version bump and lots of comments
  * New plugin structure using configurations
  * New Proguard rules, automatic generation (aapt -G)
  * Easier classpath management
  * Easier preloading, with support for arbitrary libraries
  * Many fixes (ApkLibs, test projects,...)
  * Device-specific commands don't exist anymore, use adbTarget
  * Setting for the default IntelliJ configuration