KMime: remove QStringOrQPair from the public API
Those two methods were not used outside kmime_header_parsing.cpp, so better internalize all this.
The only exception was an unfinished non-automated test program, adjusted accordingly.
Those two methods were not used outside kmime_header_parsing.cpp, so better internalize all this.
The only exception was an unfinished non-automated test program, adjusted accordingly.