Revert "don't use a segmentation path counter"

This reverts commit 5ab63d033c32a500e18f2bc4fddb6266858555fe.
better testing method for comparing relannis tab files
fixed some tests
start with 0 as segmentation index
restore testcase which requires that a virtual token needs a space as covered text
when writing to node.tab assume a virtual token consumes a space character