DWDS/Dialing Concordance Code

+ fixed annoying queries-must-end-with-whitespace bug in ddc_simple.cpp
+ re-worked "#HAS_FIELD" parsing, compilation, and evaluation routines
+ added support for negated #has filters "!#has[...]"
+ added support for negated regexes in #has expressions ("#has[x,!/r/]" acts like "!#has[x,/r/]")
+ added safe escapes for "*" wildcards in #has expressions
+ added explicit set-wise disjunction for #has expressions: #has[x,{a,b,c,...}]
+ TODO: external expansion API a la "|"-notation for #has filters