Don't reveal unseen tiles in the minimap
Update message mutation to Lua 5.1

Use #mytable instead of table.getn(mytable) and string.gmatch instead of
string.gfind.
Uppercase mid-sentence mutations at sentence starts
Preserve spacing of words/punctuation when mutating messages

This removes the weird punctuation spacing in dialog messages.

I couldn't use string.gmatch because Lua's pattern matching lacks an OR
operator (the '|' character) and its quantifiers don't work on anything
that isn't a "single character class".