Variable width bitmap symbols, colon character, refactored bitmap symbol creation arrays

Lyo,
I'm really enjoying FBDigitalFont. Nice work.

Take a look at this pull request and see what you think. I added the ability to create FBFontSymbols of any width. I added FBFontSymbolColon, which is only 3 dots wide, rather than 5. This is useful for displaying times (hour:minute:second). I refactored coordForSymbol to use @1 and @0 rather than true/false.

Thanks,
Phillip