ImportRG: Add stop_mumps_process for GT.M

Stop all active mumps processes that belong to current user before
deleting global data. If not explicitly stopped, those mumps processes
will become zombie process and the disk space that previous global data
occupied will not be released.

Also change to use explicit path to mumps commands to remove the dependency
of $gtm_dist being part of $PATH and fix an indent issue.

OSEHRA-Id: http://issues.osehra.org/browse/OAT-92
Change-Id: I520103dd1a4ca8808cbf69be85db926775af3a1b
Add flag for XINDEX Testing

XINDEX testing doesn't have its own flag to control whether testing is
ran or not (unlike all other types of tests).

Default TEST_VISTA_XINDEX to ON so the expected behavior is not
changed.

Change-Id: I2ae66c7cfab380397d2e0949c6e677144e7736f4
Merge "ImportRG: Add stop_mumps_process for GT.M"