Fix some bugs with legend dialogs.

git-svn-id: svn://anonsvn.kde.org/home/kde/branches/work/kst/portto4/kst@1358426 283d02a7-25f6-0310-bc7c-ecb5cbfe19da
Fields which are considered time fields (currently Time TIME time Temps TEMPS) will have
isTime() set to be true.
'x' and 'y' now do a better job at copying the X and Y coordinates.
Fix a bug in scalar selectors: orphan scalars generated in the combo enteries
were not properly handled.
Some more fixes for scalars/scalar selectors.
More work on scalar selectors:
You can either select a scalar, or enter a number. The number will now
be hidden from all scalar lists, because it would be... wrong to be able
to edit '3' and make it '4'.
updates for kst-build
fix some assumptions that qreal=double, should now be buildable on arm.

BUG: 317094

git-svn-id: svn://anonsvn.kde.org/home/kde/branches/work/kst/portto4/kst@1362914 283d02a7-25f6-0310-bc7c-ecb5cbfe19da