FrameSerializer version code cleanup

[yschimke]

https://github.com/ReactiveSocket/reactivesocket-cpp/blob/f1b862a23bc951bbe5869d03321eafa4f583a2a1/src/FrameSerializer.cpp

• avoid flags in library code
• handle versions greater than 9
• don't accept versions like ':.:' -> 10.10

[benjchristensen]

This code also doesn't build on many Mac machines. I have to comment it out to compile.

//DEFINE_string(
//    rs_use_protocol_version,
//    "",
//    "override for the ReactiveSocket protocol version to be used"
//    " [MAJOR.MINOR].");

static std::string FLAGS_rs_use_protocol_version = "";

[benjchristensen]

@somasun any ideas on this?

[lehecka]

we should remove the GFLAG from the library and let the application code specify the version via SetupConnectionPayload.

[benjchristensen]

Is this still needing to be done after the recent refactoring?