Replace constants.h with buildsystem defines
cmake: Replace Windows specific if(MSVC) with if(WIN32)
Merge pull request #128 from lclc/constantsh

Replace constants.h with buildsystem defines
Removed ExportWrapper.h
Removed WinsockWrapper.h
Merge pull request #136 from BugFreeSoftware/remove_wrappers

Removed ExportWrapper.h and WinsockWrapper.h