updated container mixin to be fixed-container instead so we can keep the .container in scaffolding while removing the repeated code

Conflicts:
	bootstrap-1.2.0.css

Conflicts:
	bootstrap-1.2.0.css
	bootstrap-1.2.0.min.css
	lib/patterns.less
	lib/scaffolding.less

improve CSS properties for centering content, the container, and fluid container so as to not override properties where possible

add reset filter to preboot for turning off gradients in IE when necessary; make :disabled [disabled] for crossbrowser usage

Conflicts:
	bootstrap-1.2.0.css
	bootstrap-1.2.0.min.css

Conflicts:
	bootstrap-1.2.0.css

Fix for popover issue from #136