Detect typos in issued commands

[henke37]

Sometimes commands are typed in a hurry and typos result. It'd be interesting if typos were detected and reacted to.

For example, if you typo the !bang command, the shot could fire way off the mark.

[paris-ci]

Good Idea, a few (open) questions :

• Should we do that to only some commands ? Or every command ?
• What should we do ?
• Différent things on each typo ?
• ...

[SirYwell]

I think it would be helpful on commands like !bang and !reload. A first step would be to handle them case-insensitive.
It would be also good to have aliases for some commands (that could be also a solution for #54)

[Diagamma]

Aliases already exist for !bang (using them to fix the shitty consistency is a good idea though).
About case-insensitiveness : #8