move spot/bin/ and spot/tests/ up by one level

* spot/bin/: Move...
* bin/: ... here.
* spot/tests/: Move...
* tests/: ... here.
* Makefile.am, README, bench/stutter/Makefile.am,
bench/stutter/stutter_invariance_formulas.cc, doc/Makefile.am,
configure.ac, debian/rules, spot/Makefile.am, spot/ltsmin/Makefile.am,
spot/ltsmin/kripke.test, spot/sanity/style.test, python/tests/run.in:
Adjust.

tests/.gitignore

@@ -0,0 +1,70 @@
+acc
+apcollect
+bddprod
+bitvect
+blue_counter
+checkpsl
+checkta
+complement
+consterm
+defs
+.deps
+*.dot
+eltl2tgba
+emptchk
+defs
+equals
+expect
+expldot
+explicit
+explicit2
+explicit3
+explprod
+graph
+genltl
+input
+intvcomp
+intvcmp2
+kind
+length
+.libs
+ikwiad
+ltl2dot
+ltl2text
+ltlmagic
+ltlprod
+ltlrel
+lunabbrev
+Makefile
+Makefile.in
+maskacc
+mixprod
+nequals
+nenoform
+ngraph
+output1
+output2
+parse_print
+powerset
+*.ps
+randltl
+randtgba
+readsat
+readsave
+reduc
+reduceu
+reductau
+reductaustr
+reduccmp
+reductgba
+stdout
+spotlbtt
+syntimpl
+taatgba
+tgbagraph
+tgbaread
+tostring
+tripprod
+tunabbrev
+tunenoform
+unabbrevwm