build: fix required autoconf version

Since abc2ae6 (Update AX_PTHREAD (PCRE2Project#694), 2025-02-12), when using
autoconf 2.60 with autogen, shows:

  error: possibly undefined macro: AS_ECHO

Use 2.62 instead, which include that macro, as the new required version.

Author: carenas

NON-AUTOTOOLS-BUILD

@@ -171,7 +171,7 @@ example.
      src/config.h) . Compile src/pcre2test.c; don't forget -DHAVE_CONFIG_H if
      necessary, but do NOT define PCRE2_CODE_UNIT_WIDTH. Then link with the
      appropriate library/ies. If you compiled an 8-bit library, pcre2test also
-     needs the pcre2posix wrapper library.
+     needs the pcre2posix wrapper library when linking.
 
  (9) Run pcre2test on the testinput files in the testdata directory, and check
      that the output matches the corresponding testoutput files. There are

configure.ac

@@ -22,7 +22,7 @@ m4_define(libpcre2_posix_version, [3:6:0])
 # NOTE: The CMakeLists.txt file searches for the above variables in the first
 # 50 lines of this file. Please update that if the variables above are moved.
 
-AC_PREREQ([2.60])
+AC_PREREQ([2.62])
 AC_INIT([PCRE2],pcre2_major.pcre2_minor[]pcre2_prerelease,[],[pcre2])
 AC_CONFIG_SRCDIR([src/pcre2.h.in])
 AM_INIT_AUTOMAKE([dist-bzip2 dist-zip foreign])

doc/pcre2build.3

@@ -134,8 +134,8 @@ UTF support allows the libraries to process character code points up to
 0x10ffff in the strings that they handle. Unicode support also gives access to
 the Unicode properties of characters, using pattern escapes such as \eP, \ep,
 and \eX. Only the general category properties such as \fILu\fP and \fINd\fP,
-script names, and some bi-directional properties are supported. Details are
-given in the
+script names, and some bi-directional and binary properties are supported.
+Details are given in the
 .\" HREF
 \fBpcre2pattern\fP
 .\"
@@ -152,8 +152,8 @@ request this by starting with (*UCP).
 .sp
 The \eC escape sequence, which matches a single code unit, even in a UTF mode,
 can cause unpredictable behaviour because it may leave the current matching
-point in the middle of a multi-code-unit character. The application can lock it
-out by setting the PCRE2_NEVER_BACKSLASH_C option when calling
+point in the middle of a multi-code-unit character. The application can lock
+it out by setting the PCRE2_NEVER_BACKSLASH_C option when calling
 \fBpcre2_compile()\fP. There is also a build-time option
 .sp
   --enable-never-backslash-C
@@ -517,7 +517,7 @@ use), some extra configuration may be necessary. The INSTALL file for
 If your environment has not been set up so that an appropriate library is
 automatically included, you may need to add something like
 .sp
-  LIBS="-ncurses"
+  LIBS="-lncurses"
 .sp
 immediately before the \fBconfigure\fP command.
 .