Hey,
as a vanguard of the upcoming Tomahawk 0.6 release I can already let you know that the new Jreen 1.1.1 release is out which fixes an annoying bug in Jreen 1.1.0.
That bug caused that connecting after granting auth needed a restart of Tomahawk and auth popups were opened several times...
Both issues together can lead to a very very bad first impression of Tomahawk, that's why I chose to make CMake error out when it detects that very version to be installed, Jreen 1.0.5 was fine and so is the new Jreen 1.1.1.
Best regards,
Domme
P.S.:
http://qutim.org/dwnl/44/libjreen-1.1.1.tar.bz2