Remove !important on generic link styling.

For some reason, there’s an `!important` on the generic link styling. This necessitates the use of `!important` when ever you wish to override it. Why this was ever there, I have no idea. I've tried asking @mortendk who wrote it in the first place, but he has no idea.

Since no one (to my knowledge) is using Dynamo as-is, I figured we might as well remove this rule, since all overriding theme's I've seen overrides link styling.