allow dnd into folders starting with whitespace
disable MDB2_PORTABILITY_RTRIM
fixes dnd into folders ending in whitespace on oracle
unnecessary portability option because only affects fixed length character columns. luckily we dont have that kind of columns: the text datatype is transformed into varchar by MDB2
extend unit test to directories starting or ending in whitespace
use closest instead of parent
Merge pull request #5647 from owncloud/fix4390_stable5

Fix4390 stable5