Simplifications

Separate renderer java class deleted, fixed some errors in JNI
implementation signatures.
Fix of double invocation

Fixed double invocation of NativeInterface.onCreate
Logging, GlHelper class, preprocessor definitions

Log class added, implementation for Android, iOS yet to come.
GlHelper added, one method for now - createShader.
__ANDROID__ macro is now used to define whether compiling for Android or
not.
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