lib-src/Makefile trivial simplifications

lib-src/Makefile trivial simplifications

* lib-src/Makefile.in (blessmail): Depend on lisp/mail/blessmail.el.
Use $<, $@.
(regex.o, etags${EXEEXT}, ctags${EXEEXT}, ebrowse${EXEEXT})
(profile${EXEEXT}, make-docfile${EXEEXT}, movemail${EXEEXT})
(pop.o, emacsclient${EXEEXT}, emacsclientw${EXEEXT}, ntlib.o)
(hexl${EXEEXT}, update-game-score${EXEEXT}, emacsclient.res): Use $<.
(ctags${EXEEXT}): Add $srcdir to dependency rather than using VPATH.