docker.py: use ExeConfig.bin

[graik]

docker.py currently uses a hard-coded binary path. Convert to ExeConfig usage.

See:

biskit/biskit/dock/docker.py

Lines 64 to 68 in d2d4965

	def __init__( self, recDic, ligDic, recPdb=None, ligPdb=None,
	comPdb=None, out='hex_%s', soln=512,
	recChainId=None, ligChainId=None, macDock=None,
	bin='hex', verbose=1 ): ## use ExeConfig instead of bin=...
	"""