external current in postprocessor
total current for magnetic steadystate, tests and postprocessor quantities
possibility to specify if special function belongs to given analysis -> possibility to remove total current from transient gui
fix: functions in richards added to respective analysis types
Merge remote-tracking branch 'kus/master'

Conflicts:
	agros2d-generator/generator_module.cpp
	agros2d-library/hermes2d/plugin_interface.h
automatic version_git in cmake