re-add gpio library
add gpio API to makefile, change button API to use gpio API
Set makefile to compile and setuid-root pullup.sbin before adding it to the egg.
create udev rule to allow access to gpios and add to postinstall
start implementation of edge detection for gpio
create run thread for interrupt
start implement edge detection interrupts
changed LEDSprite width and height fields to be implemented with property decorater, changed container_width and container_height to be width and height, closes #74
got interupts working!
implement debouncing, and wait_for_edge, needs testing
change interrupt polling not to open a new value file, implement set_level
small bugfix after testing
clean up some code, add timeout to interrupts
debugged set_level, renamed Port to Pin
rename 'Port' to 'Pin', fix remove_edge_detect, add remove_call_on_change
fix bug when calling call_on_change more than once
cleaning up
more cleanup
Merge pull request #77 from scottsilverlabs/dev/jpsnyder/unrooting_programs

Dev/jpsnyder/unrooting programs
merge in changes from master