DWDS/Dialing Concordance Code

* added linux kernel-style branch prediction macros likely(), unlikely()
* added index-compile-time negative-year support for CBibliography::ConvertDateToInt()
* hacked slice computation for negative years in CQCountKeyExprDateSlice::Evaluate()
+ slice labels always round *down*, even for negative slices, e.g. slice(1974/10)=1970 but slice(-1974/10)=-1980
+ without this hack, slice-label 0 would cover a 20-year interval (-10..9)

+ updated scripts/{int2date,date2int}.perl for signed-year encoding

+ added support for negative years in utilit.cpp date2int(), int2date()
- probably breaks date-savvy indexing & runtime code

+ added test for mantis #47973: double-escaped slash in CQTokRegex::toString()
- still UNRELEASED (waiting on next ddc release, v2.2.4)

+ optimized out implicit regex for negative literal filter conditions in in CFreeBiblStringIndex::GetFilterValue()

* updated version (work in progress)

+ src/CommonLib/ddcString.cpp: fix for double-escaped slashes in CQTokRegex::toString (mantis #47973)

+ tagged DDC-Concordance-0.47

+ added parseAddr() call in new() to help ensure consistent $client->{connect}

+ tagged DDC-Concordance-0.46