remove EBML_PRETTYLONGINT
remove EBML_PRETTYLONGINT

It should not be used as C++ has the proper way to express long(long) literals.

It won't be used in libmatroska after https://github.com/Matroska-Org/libmatroska/pull/90

Matroska-Org/libebml,Matroska-Org/libebml