add ClassVersion field to Synapter class; closes 78
replace .isSynapterObjectOutOfDate by isCurrent

Use Biobase generic `isCurrent` instead of `.isSynapterObjectOutOfDate` to test
for the correct version. Additionally `isCurrent`/`updateObject` are adapted to
the new `ClassVersion` field.
Merge branch 'updateSynapterObject' into 2.0

Conflicts:
	NEWS