sim: use new Migen APIs
Merge pull request #1 from kennethryerson/master

I2C Driver for PCA9555
library/rf_drivers: style
Use Mibuild
Move mmgr to library and remove tools folder
Update README
update gitignore
I2CDataWriter: bit banging
CRG: common component + separate signal and system clocks (breaks clocking)
corelogic -> genlib
Use new 'specials' API
library/ti_data: new clocking scheme (untested)
library/ti_data: fix sync clock domains
mmgr: get names from memories
ti_data: rename to ti_io + fixes
library/rf_drivers: import TSTriple
library: refactor waveform generator
baseapp: set execute permissions on bof file
ti_io: fix single-rate DAC driver
ti_io: default DAC IO test pattern