make it possible to specify the jtag cable in the environment (so a remote

make it possible to specify the jtag cable in the environment (so a remote
machine can be used to program devices and to reduce probing times)
Examples:

export CABLE='auto' (default)
	probes for cable on local machine

export CABLE='lpt1'
	uses cable on lpt1

export CABLE='auto -server marvin:2000'
	probes for cable on remotehost marvin running CableServer on port 2000

export CABLE='usb21 -server marvin:2000'
	uses usb cable on remotehost marvin running CableServer on port 2000

see Makefile for possible cabletypes and
doc/usenglish/help/iseguide/mergedProjects/plugin_imp/html/pim_batch_command_definitions_s.htm

With this it is even possible to avoid compiling windrvr:
http://sourceforge.net/projects/xilprg