CrashReporter: fix build with -Werror.
CrashReporter: fix build with -Werror.

We had no abs() declaration, presumably missing
a <stdlib.h> include.

However, instead of continuing to use abs(), the
code has been changed to use qAbs, to avoid losing
precision and to avoid type conversion from qint64
to int.

austinliou/mumble,feld/mumble,feld/mumble,austinliou/mumble,Lartza/mumble,LuAPi/mumble,SuperNascher/mumble,LuAPi/mumble,SuperNascher/mumble,LuAPi/mumble,Lartza/mumble,austinliou/mumble,feld/mumble,LuAPi/mumble,SuperNascher/mumble,austinliou/mumble,LuAPi/mumble,austinliou/mumble,LuAPi/mumble,LuAPi/mumble,SuperNascher/mumble,LuAPi/mumble,Lartza/mumble,unascribed/mumble,unascribed/mumble,SuperNascher/mumble,SuperNascher/mumble,austinliou/mumble,feld/mumble,austinliou/mumble,unascribed/mumble,SuperNascher/mumble,feld/mumble,SuperNascher/mumble,Lartza/mumble,unascribed/mumble,feld/mumble,unascribed/mumble,SuperNascher/mumble,LuAPi/mumble,feld/mumble,feld/mumble,unascribed/mumble,Lartza/mumble,austinliou/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,unascribed/mumble,unascribed/mumble