coredevice/core: core_com -> comm
transforms/inline: fix default values of positional args
dds: phase control (mostly untested)
examples: remove compiler_test
core: add underflow recovery function
runtime: use booleans in syscalls
pc_rpc: add init magic string
pyon: fraction support
transforms/fold_constants: support decimal fractions
soc/target: remap RTIO to avoid conflict with Ethernet MAC+PHY
transforms: PEP8
doc/manual: add FPGA board info and TTL line assignments
transforms/lower_units: fix bugs and add unit test
doc/manual: add ports to index
add requirements.txt