Author: Michael Bruck <mbruck@digenius.de>

    -jtag.c, interface_jtag_add_dr_scan():
            - use pointer 'field' instead of scan->fields[field_count]
            - restructure the main loop to clearly separate the two cases: TAP is not bypassed / TAP is bypassed
            - add an assert that each non-bypassed TAP receives at least one field
            - add an assert that checks that no superfluous input fields were passed



git-svn-id: svn://svn.berlios.de/openocd/trunk@1866 b42882b7-edfa-0310-969c-e2dbd0fdcd60