messages fix, add /manuclearp and /mangclearp
fix clear commands change mandemote and manpromote

dont make manpromote and mandemote act like manuadd when OP, 3 manuadd commands arent needed.
Update GroupManagerPermissions.java
add new commands, add alias to listgroups
add mising isopoverride check
fix alias
readd some checks
Merge pull request #371 from necrodoom/patch-72

add new commands and others