Release Spot 2.3.5

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

NEWS

-New in spot 2.3.4.dev (not yet released)
+New in spot 2.3.5 (2017-06-22)
 
   Bugs fixed:
 
-  - We have fixed new cases where translating multiple formula in a
+  - We have fixed new cases where translating multiple formulas in a
     single ltl2tgba run could produce automata different from those
     produced by individual runs.
 
@@ -17,6 +17,9 @@ New in spot 2.3.4.dev (not yet released)
     a number of reachable states/edges/transitions, but %S was
     incorrectly counting all states even unreachable.
 
+  - Our verson of BuDDy had an incorrect optimization for the
+    biimp operator.
+
 New in spot 2.3.4 (2017-05-11)
 
   Bugs fixed:

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], [2.3.4.dev], [spot@lrde.epita.fr])
+AC_INIT([spot], [2.3.5], [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 2.3.4
-#+MACRO: LASTRELEASE 2.3.4
-#+MACRO: LASTTARBALL [[http://www.lrde.epita.fr/dload/spot/spot-2.3.4.tar.gz][=spot-2.3.4.tar.gz=]]
-#+MACRO: LASTNEWS [[https://gitlab.lrde.epita.fr/spot/spot/blob/spot-2-3-4/NEWS][summary of the changes]]
-#+MACRO: LASTDATE 2017-05-11
+#+MACRO: SPOTVERSION 2.3.5
+#+MACRO: LASTRELEASE 2.3.5
+#+MACRO: LASTTARBALL [[http://www.lrde.epita.fr/dload/spot/spot-2.3.5.tar.gz][=spot-2.3.5.tar.gz=]]
+#+MACRO: LASTNEWS [[https://gitlab.lrde.epita.fr/spot/spot/blob/spot-2-3-5/NEWS][summary of the changes]]
+#+MACRO: LASTDATE 2017-06-22