LDAP:  Oracle compat. fix, closes #4064
LDAP: avoid PHP Warnings cause by passing empty values to implode
Oracle compat: enable appconfig.configvalue to store empty strings
Revert "Oracle compat: enable appconfig.configvalue to store empty strings"

This reverts commit 6c1e68acd8fbb98f8fbd54a38860481b4971bc28.
Oracle compat: enable appconfig.configvalue to store empty strings (now working)
Fix Updater if used with MDB2
LDAP / Oracle compatibility, make SQL syntax valid
LDAP / Oracle compatibility: sql for emptying tables
Merge branch 'stable5' into ldap_oracle_fixes
fix logical mistake in version comparison
Merge pull request #4179 from owncloud/ldap_oracle_fixes

(not only) LDAP Oracle compatiblity