blur filter
better test with animation loop (that doesn't animate anything actually) and stats counter
call premultiplyAlpha before blur
malloc/free seem to behave better than char buf[len]
some minor optimizations
disable closure compiler. problems with memory management?
remove map file after build
use .length
wrap lib to prevent global var cluttering
optimize cases where alpha == 0

unsure if i can do that in blur
write 32bit words instead of bytes
clean up

- added dat.gui
- put all filters into filters.c
- created Demo class for main app
- made raw asm.js function wrappers publicly available
- removed unpre/premultiply calls from blur()
bugfix: start with clean line/column buffers
bugfix: corrected end conditions for inner loops
center shape on screen
add firefox logo demo
tune down defaults a bit
prevent logo flicker
prevent vertical scroll
add dropshadow settings