Release Spot 2.5.2

* NEWS, configure.ac, doc/org/setup.org: Bump version.

NEWS

-New in spot 2.5.1.dev (not yet released)
+New in spot 2.5.2 (2018-03-25)
 
   Bugs fixed:
 
@@ -6,7 +6,7 @@ New in spot 2.5.1.dev (not yet released)
     acc_cond::is_generalized_streett() would segfault on weird
     acceptance conditions such as "3 t" or "3 f".
 
-  - remove_fin(), streett_to_generalized_buchi() should never
+  - remove_fin() and streett_to_generalized_buchi() should never
     return automata with "f" acceptance.
 
   - "autfilt --acceptance-is=Fin-less" no longer accept automata

configure.ac

@@ -21,7 +21,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 AC_PREREQ([2.61])
-AC_INIT([spot], [2.5.1.dev], [spot@lrde.epita.fr])
+AC_INIT([spot], [2.5.2], [spot@lrde.epita.fr])
 AC_CONFIG_AUX_DIR([tools])
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([1.11 gnu tar-ustar color-tests parallel-tests])

doc/org/setup.org

 #+OPTIONS: H:2 num:nil toc:t html-postamble:nil
 #+EMAIL: spot@lrde.epita.fr
 #+HTML_LINK_HOME: index.html
-#+MACRO: SPOTVERSION 2.5.1
-#+MACRO: LASTRELEASE 2.5.1
-#+MACRO: LASTTARBALL [[http://www.lrde.epita.fr/dload/spot/spot-2.5.1.tar.gz][=spot-2.5.1.tar.gz=]]
-#+MACRO: LASTNEWS [[https://gitlab.lrde.epita.fr/spot/spot/blob/spot-2-5-1/NEWS][summary of the changes]]
-#+MACRO: LASTDATE 2018-02-20
+#+MACRO: SPOTVERSION 2.5.2
+#+MACRO: LASTRELEASE 2.5.2
+#+MACRO: LASTTARBALL [[http://www.lrde.epita.fr/dload/spot/spot-2.5.2.tar.gz][=spot-2.5.2.tar.gz=]]
+#+MACRO: LASTNEWS [[https://gitlab.lrde.epita.fr/spot/spot/blob/spot-2-5-2/NEWS][summary of the changes]]
+#+MACRO: LASTDATE 2018-03-25