Qt: Fix monospace font in osx 10.9
Qt: Fix monospace font in osx 10.9

The "Monospace" hint was added in Qt 4.8, and it works as intended as opposed
to "TypeWriter" which fails to load a font.

zemrys/vertcoin,vertcoin/eyeglass,netswift/vertcoin,vertcoin/eyeglass,alexandrcoin/vertcoin,coinkeeper/2015-06-22_18-51_vertcoin,netswift/vertcoin,netswift/vertcoin,coinkeeper/2015-06-22_18-51_vertcoin,coinkeeper/2015-06-22_18-51_vertcoin,netswift/vertcoin,alexandrcoin/vertcoin,zemrys/vertcoin,zemrys/vertcoin,netswift/vertcoin,vertcoin/eyeglass,zemrys/vertcoin,netswift/vertcoin,vertcoin/eyeglass,alexandrcoin/vertcoin,zemrys/vertcoin,coinkeeper/2015-06-22_18-51_vertcoin,vertcoin/eyeglass,zemrys/vertcoin,alexandrcoin/vertcoin,coinkeeper/2015-06-22_18-51_vertcoin