Remove script/end script whenever possible

:Release Notes:
Upstart scripts using script/end script result in one extra /bin/sh
process hanging around eatinmg a bit of memory and such

:Detailed Notes:
Having required everyone to use script/end script instead of exec, I
inadvertently led to 70+ copies of /bin/sh leftover after booting the
machine, in addition to the extra time it took Upstart to spawn
those shells which then spawned the actual binaries.
Actually, the problems I thought were being caused by 'exec' were
actually caused by 'expect' (which we no longer try to use).
Replacing the 'script' blocks with 'exec' where possible reduced the
number of excess /bin/sh processes to 1.

:Testing Performed:
Based on #292 + this change: powerd was executed correctly
with this change and there was no /bin/sh stuff.

:QA Notes:

:Issues Addressed:
[GF-35091] Upstart scripts leaving many dangling /bin/sh procs

Open-webOS-DCO-1.0-Signed-off-by: Sangwoo Kang <sangwoo82.kang@lge.com>

Change-Id: I59158b29fe3befd507f19bbf66af374dfd02ab7d
Reviewed-on: https://g2g.palm.com/3274
Reviewed-by: Build Verification
Reviewed-by: Ed Chejlava <ed.chejlava@lge.com>
Tested-by: Ed Chejlava <ed.chejlava@lge.com>