Merge pull request #14 from mrsud/FSM-dev

replaced sys.exit with raise Exception()
fixed some bugs
some bugs solved
Merge pull request #15 from livingstore/FSM-dev

Some bugs fixed
Added IC 7412
Added IC 7420
Added IC 7421
Added IC 7421,IC 7415,IC 7422
Merge pull request #16 from livingstore/FSM-dev

Added IC 7412
changed sys.exit to raise Exception in ic
Merge pull request #17 from livingstore/FSM-dev

changed sys.exit to raise Exception in ic
Added IC7442 and IC7443
Changed README
Merge pull request #20 from Lordie12/FSM-dev

Fsm dev
Added ICs 7444, 7451, 7454, 7455, 7458 and demultiplexers
Merge pull request #21 from Lordie12/FSM-dev

Added ICs 7444, 7451, 7454, 7455, 7458 and demultiplexers