* Added missing error messages
As well as `Guild#setRolePosition` and `Guild#setChannelPosition`'s first arg validation
And fixed a typo in `Guild#setChannelPosition`
`roles` -> `channels`
* Reverted collection and Util constructors
* Removed leftover messages
Should have been in the second commit.
* It's a single invalid permission and removed unused flag error
* Fix INVALID_TOKEN -> TOKEN_INVALID as of #1703