Merge pull request #2 from mschmoelzer/master

"fsm_export" pass: fix KISS file generation.
Added support for verilog genblock[index].member syntax
Moved stand-alone libs to libs/ directory and added libs/subcircuit
Added copyright statement to readme file
Fixed typo in README
Added some additional TODO items
Added "extract" pass (not functional yet)
Added support for constant signals in "extract" pass
Implemented basic functionality of "extract" pass
Added extract -verbose and -map ilang support
Added support for simple gates with one constant input to opt_const
Fixed "extract" pass for non-optimized needles
Changed default frontend for "-" to "script" (was: "ilang")
Added "extract -constports" feature
Added port swapping and compatible types to "extract" pass
Added "help" command
Added more help messages (extract, abc, dfflibmap)
Added help msg to select command (and minor improvements)
Added help for command line options
Added online help for "show" and "hierarchy" commands