Improve configure.ac pkg-config check for qwt to try more names (wider distro coverage as naming is inconsistent across distros)
Improve configure.ac pkg-config check for qwt to try more names (wider distro coverage as naming is inconsistent across distros)

nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official