DWDS/Dialing Concordance Code

* back to qf_subcorpora in q_flag : shouldn't be allowed embedded in count-queries though (-> misleading)

* CheckSatisfiable() implementation for #HAS filters over constant attributes

+ fix request-path parsing & evaluation in branch server

+ various fixes related to :-operator
- added CHost::m_ShortName - without 'server:' prefix
- added CDDCBranchServer::m_HostMap - for less painful daughter-selection
- added CRunQueryData::ReqPath - for tracking request paths (for server VersionCompat >= 2.2.8)
- added new server command "nodes" - return list of all reachable sub*corpus paths ()

+ query parser: qf_subcorpora clause clobbers any earlier qf_subcopora (non-additive)
+ branch server: use parsed query for selecting daughter subcorpora
- syntax works, actual sub*corpus selection is still buggy

+ lexer-level tracking of qf_subcorpora request offset+length

+ fixed run_query error formatting in leaf server

+ fixed run_query error formatting in branch server (e.g. on exceptions from runq.Init(), including parse errors)

+ #prune[] implementation seems working as well as can be reasonably expected on tiny test corpus

+ track raw byte-offset in yyQLexer