Use transient instead of option as cache

[soderlind]

Transients are inherently sped up by caching plugins, where normal Options are not.

Also:

• Add $deps to wp_dynamic_css_enqueue, $deps is an array of registered stylesheet handles this stylesheet depends on.
• Reformat code according to WordPress Coding Standards

[ykadosh]

Hi there, thank you for the contribution, great PR!

The $deps array is a great solution to one of the issues that is currently pending.

Using transients is also a nice idea, however it defeats the purpose of our internal cache. We want to give the developer the option to clear the cache manually when a user changes a settings that affects the stylesheet. Using transient may cause the data to expire too often, even if the stylesheet hasn't changed. This will trigger the compiler every time and will cause a performance impact.

Regarding the code formatting - i'm following a different format, and I would need to change the entire framework's code base to match that, so i'll wait on it for now.