Build system changed

I didn't post anything here in November or December, but did some work on Androm nonetheless, both by improving features and by changing the build system.
As I had some glitches with the build in Eclipse (see the end of the "Compiling with Eclipse" page on the Wiki which I just updated) and because Google is dropping the Eclipse ADT plugin, I have moved to Android Studio.
I had to read about the gradle build first, because the export of a gradle build file in Eclipse ADT doesn't produce a working build and importing the project into Android Studio changes the directory structure, which I don't like. But I got it working, at least for the debug build - all necessary files should be in git.