ltlparse: move in parsetl/, and declare in tl/parse.hh

* src/ltlparse/public.hh: Rename as...
* src/tl/parse.hh: ... this.
* src/ltlparse/: Rename as...
* src/parsetl/: ... this.
* NEWS: Mention the change.
* README, configure.ac, doc/org/tut01.org, doc/org/tut02.org,
doc/org/tut03.org, doc/org/tut10.org, src/Makefile.am,
src/bin/common_finput.cc, src/bin/common_finput.hh, src/bin/ltl2tgta.cc,
src/kripkeparse/kripkeparse.yy, src/parseaut/parseaut.yy,
src/tests/checkpsl.cc, src/tests/checkta.cc,
src/tests/complementation.cc, src/tests/consterm.cc,
src/tests/emptchk.cc, src/tests/equalsf.cc, src/tests/ikwiad.cc,
src/tests/kind.cc, src/tests/length.cc, src/tests/ltlprod.cc,
src/tests/ltlrel.cc, src/tests/randtgba.cc, src/tests/readltl.cc,
src/tests/reduc.cc, src/tests/syntimpl.cc, src/tests/tostring.cc,
src/tl/Makefile.am, src/twaalgos/lbtt.cc, wrap/python/spot_impl.i,
iface/ltsmin/modelcheck.cc: Adjust.

src/ltlparse/.gitignore

@@ -1,14 +0,0 @@
-.deps
-Makefile
-Makefile.in
-location.hh
-ltlparse.cc
-ltlparse.hh
-ltlparse.output
-ltlscan.cc
-position.hh
-readltl
-stack.hh
-*.lo
-*.la
-.libs