vivado: make tcl a list of commands, add reporting
Signal.like: pass kwargs
Signal.__getitem__: raise TypeError and IndexError when appropriate
fhdl.structure: remove unused imports
fhdl.structure: do not permit clock domain names that start with numbers
vivado: enable bitstream compression (optional)
kc705: add spiflash pins
platforms: add -w option to bitgen_opt
platforms/kc705: read the configuration flash faster (ISE only)
kc705: enable DCI termination on DDR3
platforms/kc705: use jtaghs1_fast cable
vivado: mode batch to prevent vivado from opening tcl shell on error
vivado: add more reporting
cordic: vivado is bad at inferring compact adder/subtractor logic
add travis-ci description