print queue lengths to usb serial
can_head and can_tail changed from uint8_t to uint16_t
all queue heads and tails are now uint16_t
added usb receive function
Merge branch 'master' of https://github.com/ucdfr/Node-Beaver into develop

SPI
xx
added radio_manager. and removed my vim mks
changed SPI clock to 6Mhz, added some Type-to-ID definitions, made time_get conform to unix time
I accidentally my mks
changed some stuff
pulled from master to develop
fixed bad merge conflicts
Configured pins for SD testing
added day folder
added data string stuff
filled time struct for debugging. added time_get and time_get_unix
file system and structure created
added test write function. added queue pointers
fixed usb pos. was using uint8 instead of uint16