Checking perms for the role and channel override was messed up at some
places.

The bot now checks for permissions which have an effect if granted on a
channel override at the channel level and for permissions which only
make sense on the role level at the role level. For example, Embed Links
is checked for each channel; but Manage Emojis is checked at the role
level.

Furthermore code style changed and help for iknowwhatiamdoing was added.