Adds the browser and system as CSS classes to the body element

Adds the browser and system as CSS classes to the body element for an easy browser or system specific layout.

Advantages and Usage:
- Less HTTP-Requests than usingconditinal comments
- Creates CSS code which is easier to read/maintain than CSS hacks
- Works with all (implemented) browsers (see list below)
- Adds detection for operating systems, "mobile" and "aol"

The following browser CSS will be added:
opera, operamini, webtv, ie, iepocket, konqueror, icab, omniweb, firebird, firefox, iceweasel, shiretoko, mozilla, amaya, lynx, safari, iphone, ipod, ipad, chrome, android,
 blackberry, icecat, s60nokia, nokia
The first two parts of the browser version will be added. Examples: For Firefox 3.5.9 "firefox firefox3 firefox35" will be added, for Internet Explorer 6.0.x "ie ie6 ie60" will be added.

The following operating system CSS will be added:
windows, windowsce, apple, linux, os2, beos, iphone, ipod, ipad, blackberry, nokia, freebsd, openbsd, netbsd, sunos, opensolaris, android

The CSS code "aol" will be added for AOL browsers and "mobile" for mobile devices.