[perf-css] deleting unused CSS file.
[perf-css] decreasing selectors of collapse module.
[perf-css] Decreasing the float number in framework. From 25 to 14 floats declarations.

I just @extend the existing class .ls-float-left when needed.
[perf-css] removing -o- prefix...
[perf-css] trying to improve selectors of ls-topbar in pre-panel
[perf-css] Removing nesting selectors of ls-table component.
[perf-css] removing nesting selector of ls-area-account in ls-sidebar
Just changing the comments line markup to be more legible.
[perf-css] decreasing specificity css selector in ls-submenu
Merge pull request #1154 from diegoeis/3.4.0

Little issues to improve CSS performance and cascading