Merge pull request #185 from FenixXx/release-1.10

Bugfixes + Command Manager Plugin
Merge pull request #186 from FenixXx/release-1.10

[ADMIN] tell player why he is not allowed to use a certain command
Fix issue #183
+ cosmetic changes
Merge pull request #187 from FenixXx/release-1.10

Minor core updates + Test cases for Command Manager plugin
[TEST] make sure the cmd manager plugin commands have the desired effects