MintLucre: remove commented out code
MintLucre: cleanup #ifdef statements
MintLucre: move SetMonitor() code to caller

SetMonitor() is a Windows only helper function but not easily
recognizable as such. Moreover, it uses the same name as
functions provided by the lucre library which is confusing.
Both problems are addressed by this patch.
Merge pull request #280 from toxeus/cleanupMintLucre

MintLucre: some cleanup