Certain HTML attributes need special live-binding

[daffl]

This is a follow up on issue #157 (#234, #241, #321, #342, #343) and also related to #488. Some HTML attributes need special treatment when live binding:

• src - Should not be set with the live binding placeholder (__!!__) because it triggers a request to __!!__.
• style - Can not be set in IE with the live binding placeholder (e.g. style="background-color: {{color}}" -> background-color: __!!__) because IE tries to parse it into a CSS stylesheet and just drops any illegal CSS. It also looks like the attribute shouldn't be set using element.setAttribute('style') but element.style.cssText instead.