Update bundled PCRE2-library to version 10.23

Some manual changes done to the library were lost with this update.
They will be added in the next commit.

pcre2/doc/pcre2sample.3

@@ -1,4 +1,4 @@
-.TH PCRE2SAMPLE 3 "20 October 2014" "PCRE2 10.00"
+.TH PCRE2SAMPLE 3 "02 February 2016" "PCRE2 10.22"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "PCRE2 SAMPLE PROGRAM"
@@ -13,23 +13,28 @@ distribution. A listing of this program is given in the
 documentation. If you do not have a copy of the PCRE2 distribution, you can
 save this listing to re-create the contents of \fIpcre2demo.c\fP.
 .P
-The demonstration program, which uses the PCRE2 8-bit library, compiles the
-regular expression that is its first argument, and matches it against the
-subject string in its second argument. No PCRE2 options are set, and default
-character tables are used. If matching succeeds, the program outputs the
-portion of the subject that matched, together with the contents of any captured
-substrings.
+The demonstration program compiles the regular expression that is its
+first argument, and matches it against the subject string in its second
+argument. No PCRE2 options are set, and default character tables are used. If
+matching succeeds, the program outputs the portion of the subject that matched,
+together with the contents of any captured substrings.
 .P
 If the -g option is given on the command line, the program then goes on to
 check for further matches of the same regular expression in the same subject
 string. The logic is a little bit tricky because of the possibility of matching
 an empty string. Comments in the code explain what is going on.
 .P
+The code in \fBpcre2demo.c\fP is an 8-bit program that uses the PCRE2 8-bit
+library. It handles strings and characters that are stored in 8-bit code units.
+By default, one character corresponds to one code unit, but if the pattern
+starts with "(*UTF)", both it and the subject are treated as UTF-8 strings,
+where characters may occupy multiple code units.
+.P
 If PCRE2 is installed in the standard include and library directories for your
 operating system, you should be able to compile the demonstration program using
-this command:
+a command like this:
 .sp
-  gcc -o pcre2demo pcre2demo.c -lpcre2-8
+  cc -o pcre2demo pcre2demo.c -lpcre2-8
 .sp
 If PCRE2 is installed elsewhere, you may need to add additional options to the
 command line. For example, on a Unix-like system that has PCRE2 installed in
@@ -37,12 +42,11 @@ command line. For example, on a Unix-like system that has PCRE2 installed in
 like this:
 .sp
 .\" JOINSH
-  gcc -o pcre2demo -I/usr/local/include pcre2demo.c \e
-      -L/usr/local/lib -lpcre2-8
+  cc -o pcre2demo -I/usr/local/include pcre2demo.c \e
+     -L/usr/local/lib -lpcre2-8
 .sp
-.P
-Once you have compiled and linked the demonstration program, you can run simple
-tests like this:
+Once you have built the demonstration program, you can run simple tests like
+this:
 .sp
   ./pcre2demo 'cat|dog' 'the cat sat on the mat'
   ./pcre2demo -g 'cat|dog' 'the dog sat on the cat'
@@ -51,12 +55,13 @@ Note that there is a much more comprehensive test program, called
 .\" HREF
 \fBpcre2test\fP,
 .\"
-which supports many more facilities for testing regular expressions using the
-PCRE2 libraries. The
+which supports many more facilities for testing regular expressions using all
+three PCRE2 libraries (8-bit, 16-bit, and 32-bit, though not all three need be
+installed). The
 .\" HREF
 \fBpcre2demo\fP
 .\"
-program is provided as a simple coding example.
+program is provided as a relatively simple coding example.
 .P
 If you try to run
 .\" HREF
@@ -65,7 +70,7 @@ If you try to run
 when PCRE2 is not installed in the standard library directory, you may get an
 error like this on some operating systems (e.g. Solaris):
 .sp
-  ld.so.1: a.out: fatal: libpcre2.so.0: open failed: No such file or directory
+  ld.so.1: pcre2demo: fatal: libpcre2-8.so.0: open failed: No such file or directory
 .sp
 This is caused by the way shared library support works on those systems. You
 need to add
@@ -89,6 +94,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 20 October 2014
-Copyright (c) 1997-2014 University of Cambridge.
+Last updated: 02 February 2016
+Copyright (c) 1997-2016 University of Cambridge.
 .fi