added Creator class for filters
added description field to filter record
basic filter tree structure
added filter box and basic record filter UI (not functional yet; only supporting on-the-fly filters for now)
repalced std::auto_ptr with boost::shared_ptr in filter nodes
replaced binary filter node with a n-ary node
Re-introduce lost functionality

The branch merged in 5a863589b4 removed fine-grained configure-time control
over install paths. This is necessary to accomodate various linux distros'
policies, eg. Gentoo wants games installed in /usr/games, but with resource
files in /usr/share/games.

DOCDIR and MANDIR appear to be unused, and were not re-introduced.
cleanup

-   drop trailing slashes from paths for consistency
-   sort entries that got unsorted
Improve actor movement collision handling
Use a better method to do actor physics traces
Get rid of the old newtrace method
Clean up the trace struct
Fix tracing down
Add physics methods to queue and apply movements
Apply movement by queueing it to do later
added parser and custom filter edit widget (parser not functional yet; always returns a false boolean node)
Improve movement inertia

Handles all 3 axis. Incoming velocity is only added to inertia when
leaving the ground, and does not continually add to it.
Improve mid-air control
fixed BooleanNode constructor
apply filter to table after filter text change