prepared tests for global has_hitory and is_writeable, currently failing due to missing implementation

hasHistory works as intended with location defaults. Code-cleaning needed, still tons of debug output in.

- parser accepts comments in xml file

stripped down the tests to work with the bit of current implementation that is there, to see that this is working and not breaking again

bool check in VariableMapper to implement new functionality. Tests still failing due to missing implementation

adapted EqFct test to the mapped behaviour. Now tests are passing again, but I guess the complete adapter is still broken.

prepared test for DoocsPVFactory for Factory which uses the mapping. currently failing as implementation not complete

testVariableMapper is testing the clear function (and uses it to have a clean state for the next test)

changed signature of DoocsProcessScalar to accept a different name for the Doocs property than the PV name

implemented tests are now checking for the correct expected values (and still failing due to missing implementation