Add test=removeZZZ to remove quotes/dictcap tokens.

This is needed to facilitate using diff on sentence batch runs,
because the previous versions didn't include them.
Fix flag same-value bug. Add comments of TS_*.
Improve comments on MT_CONTR and WS_PL.
Remove () over "UNKNOWN-WORD", for token-pasting.
Fix the "dictcap" handling.

This handling is now ready for tests.
It is enabled by !test=dictcap.
In order to compare results by "diff" (actually "diff -i" for now, because the
capital letters are not restored yet), !test=dictcap,removeZZZ may be
used (to remove the dictcap tokens from the linkage results).

Dictcap handling of words that morpheme-split has not yet validated.