[cleanup] System.Web*: remove TARGET_J2EE

done using unifdef
git grep -l TARGET_J2EE | grep -v ChangeLog | xargs -n1 unifdef -m -UTARGET_J2EE

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
[cleanup] WebConfigurationManager: remove hasConfigErrors

it's not used since 2009 (6a261e04add13efa6eb43ed015ab26953c2b3a95)

Signed-off-by: Etienne CHAMPETIER <etienne.champetier@fiducial.net>
Merge pull request #1375 from echampet/cleanup

TARGET_J2EE cleanup.