LDAP Wizard: when determining objectclasses, we realy do not need to look at every entry. Fixes #7530
Fix wildcard handling and check even less DNs per filter, enough will be looked at anyway
Use the LDAP wrapper for checking resources, needs for proper testing
fix potential infinite loop when the DN of the first entry was already read.
add tests for cumulativeSearchOnAttribute
make tests work on systems without php5_ldap
define var
add comment to clearify when a skip in the foreach happens
Merge pull request #7837 from owncloud/fix_7530

LDAP: fix determining objectclasses takes long