Follow MSVC as much as possible by requiring proper dllimport/dllexport declarations.
Remove dllimport/dllexport declarations from all nsXPTCStubBase functions and just export the class itself.
Bug #226609 r=shaver/swalker sr=dbaron a=chofmann
git-svn-id: svn://10.0.0.236/trunk@154023 18797224-902f-48f8-a5cc-f745e15eee43