[dlls/dbgeng]: add initial stub dll implementation

[Volodymyr Shcherbyna]

Hello Everyone,

This is my first patch in WINE. I hope I did not do any mistakes ...

I am trying to use several windows utilities under WINE and I've noticed
that dumpchk.exe (a utility which analyzes crash dumps generated by Windows)
does not work under WINE as it requires dbgeng.dll (Debugger Engine API) to
be implemented. I decided to implement stub version of dbgeng.dll, so that
maybe me or someone else in the future will continue developing it.

Thanks,