first attempt to clean up type system
switch json api to better type system and enhance error reporting
Merge branch 'master' into proper-error-codes

Conflicts:
	libguh/devicemanager.cpp
fix merge
fix merge for real
Merge branch 'master' into proper-error-codes

Conflicts:
	plugins/deviceplugins/openweathermap/devicepluginopenweathermap.cpp
Merge branch 'master' into proper-error-codes

Conflicts:
	libguh/devicemanager.cpp
Merge pull request #39 from mzanetti/proper-error-codes

Proper error codes