Done now before their as used too widely. We are most likely to allow dev. to use custom colors soon, so we want to avoid confusing / renaming then. (iTop extensions have been verified, none had to be migrated)
Notable changes :
* extensions lists were originally UL/LI but I replaced them with Alert neutral, collapsed by default
* the "Get extensions from iTop Hub..." button was located between both fieldset. I moved it on top of the page, just below page title
