Removed RTLD_GLOBAL flag from QPluginLoader again.
Removed RTLD_GLOBAL flag from QPluginLoader again.

Adding the flag was a bad idea (should have known better).
Although it fixed the problem of "missing" type_info symbols
from DSOs loaded via dlopen() on gcc < 4.5, it had the effect
of merging all C symbols with the same name from all DSOs.
Hence, qt_plugin_instance() functions from different plugins
where merged together and ctkPluginActivator classes loaded
from the wrong plugins.

The only solution for systems with gcc < 4.5 (MacOS 10.5 and
older Linux distributions) is to use qobject_cast instead
of dynamic_cast.

Note that in gcc 4.5 the default behavior for comparing
typeinfo names has changed, so dynamic_cast across DSOs
loaded via dlopen() works.

jcfr/CTK,vovythevov/CTK,laurennlam/CTK,AndreasFetzer/CTK,CJGoch/CTK,fedorov/CTK,jcfr/CTK,ddao/CTK,lassoan/CTK,danielknorr/CTK,rkhlebnikov/CTK,finetjul/CTK,SINTEFMedtek/CTK,Heather/CTK,vovythevov/CTK,ddao/CTK,vovythevov/CTK,rkhlebnikov/CTK,finetjul/CTK,sankhesh/CTK,jcfr/CTK,fedorov/CTK,sankhesh/CTK,commontk/CTK,fedorov/CTK,pieper/CTK,mehrtash/CTK,pieper/CTK,CJGoch/CTK,finetjul/CTK,espakm/CTK,jcfr/CTK,naucoin/CTK,151706061/CTK,finetjul/CTK,Sardge/CTK,naucoin/CTK,jcfr/CTK,AndreasFetzer/CTK,AndreasFetzer/CTK,danielknorr/CTK,msmolens/CTK,pieper/CTK,Sardge/CTK,151706061/CTK,msmolens/CTK,espakm/CTK,mehrtash/CTK,AndreasFetzer/CTK,rkhlebnikov/CTK,Sardge/CTK,mehrtash/CTK,mehrtash/CTK,SINTEFMedtek/CTK,Heather/CTK,Sardge/CTK,naucoin/CTK,sankhesh/CTK,laurennlam/CTK,CJGoch/CTK,151706061/CTK,SINTEFMedtek/CTK,ddao/CTK,sankhesh/CTK,Heather/CTK,commontk/CTK,Heather/CTK,CJGoch/CTK,lassoan/CTK,ddao/CTK,laurennlam/CTK,espakm/CTK,lassoan/CTK,pieper/CTK,lassoan/CTK,naucoin/CTK,espakm/CTK,CJGoch/CTK,fedorov/CTK,commontk/CTK,SINTEFMedtek/CTK,vovythevov/CTK,rkhlebnikov/CTK,commontk/CTK,msmolens/CTK,danielknorr/CTK,151706061/CTK,msmolens/CTK,danielknorr/CTK,SINTEFMedtek/CTK,151706061/CTK,laurennlam/CTK