#16 Interface declarations [__GNUG__]

[Ruslan Garipov]

Everywhere through the 'poper.co' replace COM-like interface declarations for GCC compiler from 'class IFoo: ... {}; ... __CRT_UUID_DECL(IFoo, ...' to 'DEFINE_GUID(IFoo, ...); ... MIDL_INTERFACE(IFoo...) IFoo: ...'.

See [mingw-w64:mingw-w64:3fee81] as example.