refactor build:
- structure matches both mps and plugin
- identify possible common plugins
- move java.platform from core
- core-plugin script for core plugin
remove buildCorePlugin, add mps-core-ex (this break build)
move mps-core-ex stuff fo plugins/mps-core-ex
update build scripts and fix unitTest libs location
run GeneratorsRunner
remove obsolete xml
fix plugin script
Merge remote-tracking branch 'origin/master' into julia/build
rebuild