ctkConsole: Do not allow moving before the interactive position
ctkConsole: Do not allow moving before the interactive position

This commit fixes regression introduced by the following
commits:
* b1f69f2 (ENH: Removed low-level key processing from ctkConsolePrivate::keyPressEvent)
* cac06a2 (BUG: Fixed more keyboard shortcuts in console)
* aaaa638 (BUG: Fixed Console Shift+Home behavior)

CJGoch/CTK,AndreasFetzer/CTK,fedorov/CTK,jcfr/CTK,jcfr/CTK,commontk/CTK,AndreasFetzer/CTK,sankhesh/CTK,rkhlebnikov/CTK,ddao/CTK,msmolens/CTK,laurennlam/CTK,Sardge/CTK,SINTEFMedtek/CTK,jcfr/CTK,commontk/CTK,naucoin/CTK,SINTEFMedtek/CTK,CJGoch/CTK,mehrtash/CTK,fedorov/CTK,Sardge/CTK,laurennlam/CTK,CJGoch/CTK,ddao/CTK,naucoin/CTK,rkhlebnikov/CTK,rkhlebnikov/CTK,SINTEFMedtek/CTK,Sardge/CTK,Heather/CTK,Heather/CTK,151706061/CTK,laurennlam/CTK,sankhesh/CTK,msmolens/CTK,commontk/CTK,AndreasFetzer/CTK,CJGoch/CTK,mehrtash/CTK,rkhlebnikov/CTK,fedorov/CTK,151706061/CTK,msmolens/CTK,151706061/CTK,ddao/CTK,sankhesh/CTK,Sardge/CTK,naucoin/CTK,Heather/CTK,laurennlam/CTK,naucoin/CTK,fedorov/CTK,ddao/CTK,Heather/CTK,sankhesh/CTK,mehrtash/CTK,CJGoch/CTK,jcfr/CTK,mehrtash/CTK,commontk/CTK,SINTEFMedtek/CTK,151706061/CTK,SINTEFMedtek/CTK,151706061/CTK,AndreasFetzer/CTK,msmolens/CTK,jcfr/CTK