Add assignment of "buffer size" parameter when buffer is succesfully assigned (in buffer-oriented methods)

[phomm]

For example in DGLE_RESULT DGLE_API CHDDFileIterator::FileName(char *pcName, uint &uiCharsCount) succesfull part of method is if (strlen(_acName) < uiCharsCount) { strcpy(pcName, _acName); return S_OK; } adding uiCharsCount = strlen(_acName) + 1; makes it more convenient to interoperate