maint: Preparing 3.5.2

[Akim Demaille]

I have been waiting for feedback about a couple of bug reports since 3.5.1, but 
there's nothing in sight.  We should not wait any longer to release 3.5.2.

I have cherry-picked the following commit from master:


https://lists.gnu.org/r/bison-patches/2020-02/msg00041.html
commit 57b035a242b15409643a6a8d2ceded5f9380a2cb
Author: Akim Demaille <address@hidden>
Date:   Mon Feb 10 20:12:10 2020 +0100

    doc: spell check
    
    * doc/bison.texi: here.


https://lists.gnu.org/r/bison-patches/2020-02/msg00034.html
commit 47850d4f581c337f71d20432867d8b13c66f5d60
Author: Akim Demaille <address@hidden>
Date:   Sun Feb 9 15:33:21 2020 +0100

    doc: clearly state that %yacc only makes sense with yacc.c
    
    * doc/bison.texi: here.


https://lists.gnu.org/r/bison-patches/2020-02/msg00026.html
commit fb554c28043560788fbed217d1db22696aa79ea5
Author: Akim Demaille <address@hidden>
Date:   Sat Feb 8 11:22:52 2020 +0100

    m4: fix b4_token_format
    
    We used to emit:
    
        /** Token number,to be returned by the scanner.  */
        static final int NUM = 258;
        /** Token number,to be returned by the scanner.  */
        static final int NEG = 259;
    
    with no space after the comma.  Fix that.
    
    * data/skeletons/bison.m4 (b4_token_format): Quote where appropriate.


https://lists.gnu.org/r/bison-patches/2020-02/msg00009.html
commit 9ed802a0269ad180dbae4070841bd8a118f49e2f
Author: Akim Demaille <address@hidden>
Date:   Sat Feb 1 10:41:44 2020 +0100

    java: avoid trailing white spaces
    
    * data/skeletons/java.m4 (b4_maybe_throws): Issue a space before when 
needed.
    * data/skeletons/lalr1.java: Avoid trailing spaces.


https://lists.gnu.org/archive/html/bison-patches/2020-01/msg00102.htmlcommit 
468b68c5cd8a8952574edf546dee27e34efd925b
Author: Akim Demaille <address@hidden>
Date:   Sat Jan 25 10:02:04 2020 +0100

    doc: update Doxygen template
    
    * Doxyfile.in: Run doxygen -u on it.


https://lists.gnu.org/r/bison-patches/2020-02/msg00042.html
commit 2f23ca6f653f7f64cb312c8f041eb5fa59cb0443 (HEAD -> maint, origin/maint)
Author: Akim Demaille <address@hidden>
Date:   Thu Feb 13 08:06:27 2020 +0100

    gnulib: update