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.

bin/README

@@ -0,0 +1,52 @@
+This directory contains the source of some command-line tools that
+expose some of Spot's algorithms to Unix users.
+
+Man pages are generated from the --help output of each tool,
+supplemented by any text in the man/*.x files.  Usually the extra text
+contains either some bibliographical references, some formal
+definitions or some examples that are too long for --help.  Having a
+few short examples at the end of --help is good.
+
+This directory also build some non-installed binaries, like spot-x,
+whose purpose is just to generate a man-page with the same format as
+the other man pages (this includes keeping the version number
+up-to-date).
+
+There is also a script called 'options.py' that summerizes how the
+different short options are used among the tools.
+
+Routines that are shared by multiple command-line tools are stored in
+files called common_*.{cc,hh}.
+
+
+Recommendations when adding new tools or features:
+--------------------------------------------------
+
+ - Tools should be designed to work on multiple inputs (e.g., read
+   different outputs from multiple files, and accept many inputs from
+   the same file, including stdin).  They should also all be designed
+   to produce several outputs, usually one per input.  This way they
+   can be piped one onto the other easily.
+
+ - When naming an option, seek inspiration from the POSIX standard, or
+   from GNU extensions.  For instance ltlfilt and autfilt both have a
+   -v option to invert the filter; this is inspired from grep's -v
+   option.  The long version of this option (--invert-match) is also
+   the same as in grep.
+
+ - When adding a new option, implement only the --long-option by
+   default.  Do not add a short version unless
+     (1) you are sure it will be frequently used interactively
+         (if it is only used in scripts, then a long option is enough)
+     (2) this option can be shared by multiple tools.
+
+ - As much as possible, use the same option names across tools.  Use
+   the script options.py in this directory to check what short options
+   are used.  It's OK if the same short option correspond to different
+   long names in the various tools, as long as the intent is similar.
+   For instance -n has different long options depending on the tool:
+     autfilt -n N     means   --max-count=N
+     randltl -n N     means   --formulas=N
+     randaut -n N     means   --automata=N
+  but in all cases, the intent is to specify the number of items
+  to output.