Console.log terminal-styles get converted to style formatters

Works in Firebug and Chrome.
Example: console.log("[31mRed[39m") becomes console.log("%cRed",
"color: red");
[bugfix] if length of format specifiers is 0 must be checked first!
check when logging just an object
added config, rewrote stylize-function
[Fixes #10] Don't interfere with console functions other than `log`
Added colored logging test and cleaned up code a bit (fixed accidental
global variables, etc...)