renewed rst files for documentation
added icon for PCPPlugin button
Merge branches 'development' and 'master' of https://github.com/TUB-Control/PaPI into development
save/load parameter
Merge remote-tracking branch 'origin/development' into development

Conflicts:
	papi/testcfg.xml
save/load parameter
added do_delete to gui_api,
modified the processing for stop_plugin and close_plugin to functioning correct
added tests for pl delete
added error codes v. 0.1
added a event class system for replacing PapiEvent and used it in core
changes due to new gui structure
many things
many things
changes due to new gui structure
Merge remote-tracking branch 'origin/development' into development

Conflicts:
	papi/core.py
	papi/tests/TestCoreMock.py
many things
Merge remote-tracking branch 'origin/development' into development
changes due to new gui structure
Merge remote-tracking branch 'origin/development' into development
changes due to new gui structure
many things
changes due to new gui structure
Merge remote-tracking branch 'origin/development' into development