G-API args serialization
* args serialization
* GRunArgP draft
* UMat added
* bind added
* DmitryM's review addressed. Code clean up required.
* fix android build
* bind test added
* more comments addressed
* try to fix Mac build
* clean up
* header-based generic implementation (GRunArg)
* clang again
* one more attempt for clang
* more clean up
* More Dmitry's comments addressed.
* monostate removed
* Top level functions and some other comments addressed.
* fix warnings
* disable warning