Changing the definition of StarObject::JITUpdate() from JITUpdate(

KStarsData * ) to JITUpdate( void )

This is more efficient since there's one less argument to keep passing
around.

Instead JITUpdate gets its access to data from KStarsData::Instance().

I've made data within JITUpdate static. This could be a problem if
KStarsData is ever destroyed or recreated before the program
terminates! But that should not happen anyway, because it's going to
set a whole bunch of other things haywire as well.

Otherwise, this should introduce no bugs.

CCMAIL: kstars-devel@kde.org