xbmc: merge 'gputemp' script with 'cputemp'

usage:
<cputemp [cpu|gpu]>
  to show CPU or GPU temperature, without any parameters the CPU temperate is shown
<gputemp>
  to show the GPU temperature if 'gputemp' is a symlink to 'cputemp'

Signed-off-by: Stephan Raue <stephan@openelec.tv>
Merge branch 'master' of github.com:OpenELEC/OpenELEC.tv