Added benchmark scripts

Added benchmarks scripts to time the dependance on the threads.
fixed some stuff in the bench queue
Device was not beeing passed in test/bench.sh
Merge branch 'master' into benchmark
Fixe a bug in platform detection

If there was a device with no gpu before a device with gpus the program would exit prematurly.
Merge branch 'master' of https://github.com/LJMD-OpenCL/ljmd-opencl
Fixed the benchmark script as the name of the excecutable was changed

test/bench.sh
Merge branch 'platform-detection-fix'
Made benchmarks in a loop.

	modified:   test/bench-queue.sh.dummy
Added multiple GPU support

Added multiple GPU support which is triggered by
appending a number directly to the gpu option
(e.g. gpu2 means two gpus will be used).
Each gpu is only calculating a subset of the forces
which are then downloaded to the host and redistributed
to the gpus.
Updated README wrt. command line parameters
Merge branch 'platform-detection-fix' of git://github.com/ajasja/ljmd-opencl into ajasja-platform-detection-fix
fix lines overlap
Merge branch 'ajasja-platform-detection-fix' into amdlocal
Intel compilers argo