Improve error message.
Improve error message.

Now;
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Parse error in line 364:
    span4_y9_g7_10 <-> span4_x3_g13_5

conflicting bits ['!B12[8]', '!B12[9]', 'B12[10]']
 setting:{(12, 10)}                     - current clear:{(12, 10), (12, 8)}
clearing:{(12, 9), (12, 8)}             - current set  :{(12, 9)}
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Previously;
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  File "icebox_hlc2asc.py", line 742, in apply_directive
    self.set_bits(bits)
  File "icebox_hlc2asc.py", line 762, in set_bits
    raise ParseError("conflicting bits")
TypeError: __init__() takes 1 positional argument but 2 were given
-----------------

SymbiFlow/icestorm,SymbiFlow/icestorm,SymbiFlow/icestorm,SymbiFlow/icestorm