VMUI.vi can terminate itself.

This change will make VMUI check the validity of VariableManager
reference and subpanel reference every 10 seconds.  If the reference is
no longer valid, VMUI.vi will detach and stop itself.
Fix wrong termination code

change ok button to false at termination
Address issue #35

Make change to both variable and sequence index.
Revert "Address issue #35"

This reverts commit 1e6147d7b4eccb45ed800169cdba4cc1a27c2576.