Bugfix: behavior of zero widget

Thanks to Stephen Bauters for reporting the bug
Bugfix: typo fixed
Improvement: poisson noise option for spectra

after merging with devel-updater, add appropriate code for preferences
Bugfix: clean error handling of xmimsim with wrong number of args
Improvement: time markers in console log
Improvement: added xmso2 utilities to Mac bundle
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