systems. We'll probably add another type sometime in the future,
with our own indexing system (maybe like MediaWiki's).
+sessions
+--------
+
+Session handling.
+
+handle: boolean. Whether we should register our own PHP session-handling
+ code (using the database and memcache if enabled). Defaults to false.
+ Setting this to true makes some sense on large or multi-server
+ sites, but it probably won't hurt for smaller ones, either.
+debug: whether to output debugging info for session storage. Can help
+ with weird session bugs, sometimes. Default false.
+
Troubleshooting
===============