add global.h containing PREFIX and make use of it in all sub-modules,
add PREFIX and LIBPREFIX to the qmake .pro files (allows to change prefix and libdir using <qmake PREFIX=/usr LIBDIR=/usr/lib/x86_64-linux-gnu/> or whatever)
update debian packaging scripts accordingly
debian/changelog update
change debian/source/format to git instead of quilt
fixes in debian/rules
fix prefix in debian/*.install
fix typo
add debian prefix patch