[Pm-utils] Mostly trivial security and correctness updates

[Victor Lowther]

This patch series contains mostly trivial security and correctness fixes. 
All the patches are standalone, with the exception of the 90clock lock update,
which relies on the new restrictions placed on taking and releasing locks.

The patch that will probably cause the most pain is the one that changes tests
for file existence to tests that the file exists and is owned by the user 
running the script when we are executing, sourcing, or reading from files that
are internal to the pm-utils package.  I don't mind if we end up dropping that
patch, but the more pedantic the better when it comes to security. :)

Change overview:
 pm/functions.in        |   63 ++++++++++++++++++++++++++++-------------------
 pm/module.d/tuxonice   |    2 +-
 pm/sleep.d/01grub      |    1 +
 pm/sleep.d/05led       |    4 +-
 pm/sleep.d/20video     |   12 ++++----
 pm/sleep.d/90clock     |    3 +-
 pm/sleep.d/94cpufreq   |    2 +-
 pm/sleep.d/95led       |    2 +-
 pm/sleep.d/99video     |   10 ++++----
 src/on_ac_power        |    6 ++--
 src/pm-action.in       |    2 +-
 src/pm-powersave.in    |    2 +-
 12 files changed, 60 insertions(+), 49 deletions(-)
 mode change 100755 => 100644 src/pm-is-supported.in