Add icon for interface.
For the release:
- announce build bed
- abandon old scripts: mirror-*, rsyncisabelle
- abandon old cache
- cleanup old dist
- redirect link -> proper sublinks
- cleanup website mess (new dir "projects/")
In the mid-time:
- a gentle intro enumeration on Home - "Why Isabelle?"
* stably running, mature system
* (something to say about Isar?)
* big library
* big community
* it's free
* ...
(to discuss)
- clarify relationship of "overview" and "logics":
* overview: Isabelle/HOL
* logics: Isabelle system
(to discuss)