Change autoconf version to 2.62 and automake version to 1.11.2

On my computer, the version of autoconf is 2.59 and automake is 1.9
I build with autogen.sh & configure & make and failed.

I find In Makefile.am:
    include/event2/event-config.h: config.h make-event-config.sed
        $(AM_V_GEN)test -d include/event2 || $(MKDIR_P) include/event2
        $(AM_V_at)$(SED) -f $(srcdir)/make-event-config.sed < config.h > $@T
        $(AM_V_at)mv -f $@T $@

There are three undefined variables: MKDIR_P, AM_V_GEN and AM_V_at.
Then I tried:
- autoconf-2.60 / automake-1.10
- autoconf-2.61 / automake-1.11
- autoconf-2.62 / automake-1.11.2

And only autoconf-2.62 & automake-1.11.2 is ok.

Therefore, I recommend changing the autoconf version from 2.59 to 2.62
and automake version from 1.9 to 1.11.2.

Plus autoconf 2.59 is too old - 2003.12.16 [1], so as automake 1.9 -
2004.08.11 [2], while $(AM_V_GEN)/$(AM_V_at) had been introduced in
371a1237 back in 2012.

  [1]: http://ftp.gnu.org/gnu/autoconf/
  [1]: http://ftp.gnu.org/gnu/automake/

Fixes: 371a1237 ("Make quiet build even quieter")
(cherry picked from commit 1947dd0ddbced0d8f9891656c820353f82261c52)

Makefile.am

@@ -5,8 +5,8 @@
 # See LICENSE for copying information.
 
 # 'foreign' means that we're not enforcing GNU package rules strictly.
-# '1.9' means that we need automake 1.9 or later (and we do).
-AUTOMAKE_OPTIONS = foreign 1.9 subdir-objects
+# '1.11.2' means that we need automake 1.11.2 or later (and we do).
+AUTOMAKE_OPTIONS = foreign 1.11.2 subdir-objects
 
 ACLOCAL_AMFLAGS = -I m4
 

configure.ac

@@ -6,7 +6,7 @@ dnl
 dnl Original version Dug Song <dugsong@monkey.org>
 
 AC_INIT(libevent,2.1.10-stable)
-AC_PREREQ(2.59)
+AC_PREREQ(2.62)
 AC_CONFIG_SRCDIR(event.c)
 
 AC_CONFIG_MACRO_DIR([m4])