ensure that all libraries link against all direct dependencies

ensure that all libraries link against all direct dependencies

 * src/**/Makefile.*.lib: set DLL_(D)LIB correctly.  Break the dependency
   loop between libxblast and libxalgoblastdbindex by having the former
   provide only the C++ BLAST API, leaving the C core only in libblast.
 * src/build-system/library_relations.txt: Change xblast's
   relationship to blast from includes to needs, accordingly.
 * src/algo/blast/Makefile.blast_macros.mk: Add blast to BLAST_LIBS.
 * src/algo/blast/dbindex*/*/Makefile.*.app: Link against libxconnect
   rather than libconnect for consistency with libblast, which uses the
   former to keep the aforementioned cycle-breaking from causing
   inconsistency elsewhere.

Debian-Bug: 633567.
Author: Aaron M. Ucko <ucko@debian.org>
Last-Update: 2016-12-05

Gbp-Pq: Name fix_lib_deps