initial work on opencl

cannot be properly tested due to possible bug in Apple's OpenCL GPU
implementation...

Seems to do fine on CPU though
works more or less

need to execute 4 kernels
Seems to work better now, using 64 kernels...

huge performance gain noticed
need to validate results better though

also need to put all of this in a module
plugin written and working
opencl device versionc check included
Fortified opencl support. Works fine in Mac bundle

Needs to be tested on Windows and RPMs
Merge branch 'bugfixes' into opencl

Also made some minor changes to the Makefile where it concerns the
plugin: only the shared library will be built and windows support should
be fine now but remains untested

Conflicts:
	bin/xmimsim.c
	include/xmi_data_structs.h
	src/Makefile.am
	src/xmi_aux_f.F90
small bugfix: gmodule.h should only be included with opencl support
Bugfix: poisson random distribution cannot handle huge numbers

Thanks to Jan Garrevoet for reporting this issue
Improvement: debian support added

tested on debian squeez, ubuntu will follow
Improvement: two changes from debian build merged in
added xraylib libs to bin Makefile for Ubuntu
Bugfix: GNOME desktop file

added trailing semicolon where necessary
Bugfix: moved pkgconfig file to devel package in RPM
Bugfix: URL in about window credits section
Bugfix: AS_INIT line removed in configure.ac

Was causing problems on Ubuntu 12.10: bash went crazy
Additional LIBS necessary for compilation on Ubuntu 13.04
url and email support added to about dialog

tested only on Mac OS X so far
number of cpus problem fixed?

works on Mac OS X
added config.h header to all source files