* fix: votedelete and starboard works on uncached messages

I saw an issue Ian raised about wanting a way to (a) communicate to the server through the bot (b) have the server communicate to him through the bot and the idea seemed funny so I coded it - there's little error handling, no accounting for excess characters, no graphics and attachment handling, and definitely no spam prevention - however I am sleep deprived and wanted to make what is basically a letter mail system work to a reasonable extent.

Modified sherpmail cog from a cosmetic perspective based on inputs from Matt; added sherpmail cog to init file for setup and consistency