show an useful error message when invalid characters occur in a hex entity

--HG--
branch : trunks
replace nice C style operators with Ppascal abominations

--HG--
branch : trunks
replaced exit(.) with result := .; exit

--HG--
branch : trunks
change line endings (->crlf)

--HG--
branch : trunks
Delphi 4 compatibility: overloads, replace arbitrary pointer arithmetic with pansichar, own unicode conversion function, own isnan/strtobooldef/DivMod

--HG--
branch : trunks
change lineending

--HG--
branch : trunks
fix IsNan, Delphi compatible tests (do not run array tests, overload cannot be resolved)

--HG--
branch : trunks
fix utf-8 decoding for > $10000 characters, utf-8 -> utf-32 conversion

--HG--
branch : trunks
fix StrToBoolDef

--HG--
branch : trunks