* Removed specialization.

* Removed united

original commit: 651967b9

[G-API]: Add four kernels to parse NN outputs & provide information in Streaming scenarios

* Kernels from GL "blue" branch, acc and perf tests

* Code cleanup

* Output fix

* Comment fix

* Added new file for parsers, stylistic corrections

* Added end line

* Namespace fix

* Code cleanup

* nnparsers.hpp moved to gapi/infer/, nnparsers -> parsers

* Removed cv:: from parsers.hpp