Fixed some formatting bugs
Added support for even more numerous and complex CSS selectors by circumventing an unnecessary validation step.

- window.onload occasionally incompatible behavior fixed. This had resulted in existing styles to not be applied.
- More complex and multiple CSS selectors are now supported.

Toolbar editor can be used to set custom CSS rules and view them.
Persistent custom style rules is supported.
Firefox Sync storage is supported for multi-device use.