updated trikita.obsqr information, added 3.0 release

Trikita Obsqr has been added to F-Droid long time ago, it was located on bitbucket then. Now it's moved to github and got some improvements.

Since Gradle still doesn't work well with NDK (and probably never will), we've decided to keep prebuilt zbar libraries in the source tree to simplify local builds, tests and CI on Travis. Unfortunately, this means that prebuilt zbar libraries are to be excluded from checks.

I don't know if it's technically possible to build zbar separately and ensure that Obsqr is built from pure sources. I tried using prebuild command, but my build failed, so I ended up just excluding those *.so files for now, sorry.