(re)add explicit =-operator that doesn't copy the needed state
clean up splicing and fix some problems with reindexing clean images
Merge branch 'api_change' into c++11

Conflicts:
	lib/Core/CoreUtils/propmap.cpp
	lib/Core/DataStorage/image.cpp
add/fix splcing tests for PropMap
don't hide repeating log messages when running debug code
rename non-const version of PropertyMap::property to touchProperty
add byteswapTest to CTest
build (and test) api_change in travis
Merge branch 'master' into api_change
Merge branch 'api_change' into c++11

Conflicts:
	lib/Core/DataStorage/image.cpp
	lib/ImageIO/imageFormat_nifti_dcmstack.cpp
	tests/DataStorage/chunkTest.cpp
	tests/DataStorage/imageTest.cpp
replace some boost::lexical_cast by std::stoX