Add filter for member event permissions in admin

Ghost User
2017-03-29T20:17:23+02:00

Closes #362

Before:
1. Go to the member admin
2. Try to find out which members are not allowed on events
3. You fail

After:
1. Go to the member admin
2. Try to find out which members are not allowed on events
3. Use the even...

Closes #362 (closed)

Before:

1. Go to the member admin

2. Try to find out which members are not allowed on events

3. You fail

After:

1. Go to the member admin

2. Try to find out which members are not allowed on events

3. Use the event permission filter and succeed