[commhistory-daemon] Build with either Qt4 or Qt5

Also includes some adaptation to the qtcontacts-sqlite backend.
[commhistory-daemon] Force the contacts backend selection in qt5

qtpim does not yet support the QTCONTACTS_MANAGER_OVERRIDE mechanism
for selecting the default contacts backend.
Merge pull request #8 from matthewvogt/qt5

[commhistory-daemon] Build with either Qt4 or Qt5