DWDS/Dialing Concordance Code

+ renamed bogus tag ddc-trunk-2.0.51

+ tagged ddc-trunk-2.0.51

+ extra cleanup for v2.0.51 release

+ cleanup for v2.0.51 release

+ cleaned up debugging code

* re-factored result-sorting code; debugging stuff still in place (mostly to be removed at next checkin)

+ fixed ngram-counting bug: count("$p=V*=1 $p=V*=2" #nosep) #by[$l=1,$l=2]
- counts were absurdly high and wrong
- workaround evaluates daughter query in #SEPARATE mode even for count-query in #JOIN mode, but counts each count-key at most once per hit
- generic result-sorting: added CQueryResult::sortByIndex(), ::sortByHit(), and ::mapIndex, struct CQueryResultIndex, and template CResultHitLess<>
~ because new #JOIN counting strategy requires that result hits are sorted by BreakNo
"

+ ConcIndexator : tab-dump fix: include break-indices in tab-dumps, not just token-indices
- new break format for tab-dumps: "%%$DDC:BREAK:" BREAKNAME "[" BREAKNO "]=" TOKNO_BREAKEND

+ created branch ddc-2.0.50+threaded-server from trunk revision 724