Open CouchDB maintenance section about keeping CouchDB live and well.

Import Compaction article. Source: http://wiki.apache.org/couchdb/Compaction
Make builtin reduce functions definition referenceable.
Describe some performance tips.

Source: http://wiki.apache.org/couchdb/Performance
Swap maintenance-replication sections.
Make main page a bit nicer and friendly.

Looks weird and empty, but we'll fix it later with more content and redesign.
Add missed theme's files.