added new units for distance, angle and temperature to unitconverter.
changed temperature functions in unitconverter to convert between different temperature units.
bugfix watchwindow. thread conflict. too many threads interacted with sensor.
sensor config of station has own dialog now. #23
deleted this from featuredata dialog.
fixed digits for ijk and scale.
fixes #43
closes #43
openIndy now displays the number of current valid observations and total observations of a feature.
the display style is:   valid observations / total observations.
closes #14
The index is now checked, if valid or not, so openIndy does not crash when you selected a column or row header.
fixes #44
openIndy now checks the import file. if there is no file selected, it will display a messagebox and abort the import without crashing.
fixes #45
continue implementing OiFeatureState
Merge branch 'task_Jens' into task_benedikt

Conflicts:
	controller/controller.cpp
	openIndy.pro
	src/geometry.cpp
	src/geometry.h
	src/station.cpp
	ui/edittrafoparamdialog.cpp
	ui/featuredata.cpp
	ui/featuredata.h
	ui/importnominalgeometrydialog.h
	ui/mainwindow.cpp
	ui/mainwindow.h
	ui/nominaldatadialog.cpp
	ui/readingmodel.cpp
Update Default Plugin to work with the new OpenIndy version
bugfix plugin