first attempt to implement quadtree, not working yet
still not working, testing new quadtree for each update for debugging
quadtree seems to be working for circletest, added quadtree timer to avoid updating quadtree too often
added console log message for debugging
fixed bug in quadtree collision detection by returning false unless the neighbor.react = true in element.collision_detect. trying to refactor to allow a single quadtree and neighbor list for improved computational efficiency
refactored quadtree-optimized collision detection by moving it into the Collision module as a class variable, making a single quadtree globally accessible to all elements. seems to be working with circletest
looks like dronewar is now working with quadtree-optimized collision detection
updated game.start and extended game from circletest to remove redundant code, fixed bugs in dronewar, added init() to element, and changed quadwait to 33 + 1/3
got polygontest working with quadtree
merged from issue 8 branch, automerge failed
fixed unresolved conflicts that were added accidentally on last commit
refactored dronewar ship bullet parameters into ship module and cleaned up dronewar root element, fixed some bugs in menu
tweaked dronewar and animation speed parameters based on gameplay testing using a core 2 duo laptop with 4GB RAM
updated dronewar parameters to make it more closely resemble the original version published on gameprez.com about a week ago
fixed a bug in polygontest (bullets destroying root) and tweaked initial spacing of circles and polygons in circletest and polygontest to reduce number of objects in contact at t=0 to avoid triggering too many transitions simultaneously on first contact