* src/ltlast/formula.hh (hash): Remove const from return type.
This kills a g++-4.3 warning.
* src/misc/hash.hh: Adjust to use unordered_set and unordered_map
from TR1 when g++-4.3 is used.
* src/evtgba/product.cc, src/ltltest/randltl.cc,
src/ltlvisit/randomltl.cc, src/ltlvisit/tostring.cc,
src/misc/freelist.hh, src/misc/optionmap.cc,
src/tgba/tgbareduc.hh, src/tgbaalgos/gv04.cc,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/randomgraph.cc,
src/tgbatest/ltl2tgba.cc, src/tgbatest/randtgba.cc,
src/ltltest/equals.cc, src/ltltest/readltl.cc,
src/ltltest/reduc.cc, src/ltltest/syntimpl.cc,
src/ltltest/tostring.cc, src/tgbatest/ltlprod.cc,
src/tgbatest/powerset.cc, src/tgbatest/explprod.cc,
src/tgbatest/mixprod.cc, src/tgbatest/readsave.cc,
src/tgbatest/reductgba.cc, src/tgbatest/tgbaread.cc,
src/tgbatest/tripprod.cc, src/evtgbatest/product.cc,
src/evtgbatest/readsave.cc, src/evtgbatest/ltl2evtgba.cc,
src/evtgbatest/readsave.cc: Add missing includes.
* src/tgbatest/explicit.test, src/tgbatest/explprod.test,
src/tgbatest/explpro2.test, src/tgbatest/troprod.test,
src/tgbatest/emptchk.test: Cope with different outputs.

Initialize tmp to suppress a GCC 4.0 warning.
* src/ltltest/randltl.cc (main): Likewise with another variable.

* src/ltltest/randltl.cc: Typo.

* src/tgbaalgos/ndfs_result.hxx: Implement the spot::acss_statistics
interface.
* src/tgbaalgos/magic.cc, src/tgbaalgos/se05.cc, src/tgbaalgos/tau03.cc,
src/tgbaalgos/tau03opt.cc: Add to each heap class a method returning its
size.

* src/ltltest/reduc.test: Use randltl -u, and run it through valgrind.

* src/ltlvisit/Makefile.am (ltlvisit_HEADERS,
libltlvisit_la_SOURCES): Distribute them.
* src/ltltest/randltl.cc: New file.
* src/ltltest/Makefile.am (LDADD): Link with ../libspot.la directly.
(noinst_PROGRAMS, randltl_SOURCES): New.
(EXTRA_DIST, CLEANFILES): The list of random formulae is now generated.
* src/ltltest/formulae.txt: Delete.
* src/ltltest/reduc.test: Use randltl to generate formulae.
* src/ltlvisit/length.cc (length_visitor): Fix computation
of the length of multops.
* src/ltlvisit/length.hh (length): Document the length of multops.