Fix typo in regex

There were some missing vertical bars in a regex, affecting AC_FATAL,
AC_INCLUDES_DEFAULT, and AC_LANG_... macros.
Deprecated Autoconf macros in 2.68

Move AC_FUNC_ERROR_AT_LINE, AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK,
AC_FUNC_MKTIME, and AC_FUNC_STRTOD to the deprecated highlighting
section.
New Autoconf macros in 2.69

This adds AS_EXECUTABLE_P (m), AC_CHECK_HEADER_STDBOOL (none),
AC_FC_CHECK_BOUNDS (ss), AC_F77_IMPLICIT_NONE (ss), AC_FC_IMPLICIT_NONE
(ss), AC_FC_MODULE_EXTENSION (none), AC_FC_MODULE_FLAG (ss),
AC_FC_MODULE_OUTPUT_FLAG (ss), AC_FC_PP_SRCEXT (mss), and
AC_FC_PP_DEFINE (ss), new Autoconf macros in version 2.69.
Changes for Automake 1.11.2

Add AM_PROG_AR m4 macro, and change the DISTCHECK_CONFIGURE_FLAGS
variable to AM_DISTCHECK_CONFIGURE_FLAGS.
Deprecated macros in Automake 1.11.3

Deprecate macro AM_WITH_REGEX.
Changes in Automake 1.12

Deprecate m4 macro AM_PROG_CC_STDC, and add Automake variables
AM_TESTS_ENVIRONMENT and AM_TESTS_FD_REDIRECT.
New syntax in Automake 1.12.5

Change AM_PROG_VALAC from (m) to (mss) arguments.
Changes in Automake 1.13

Add the m4 macro AM_EXTRA_RECURSIVE_TARGETS (m), and remove the Automake
variable ACLOCAL_AMFLAGS.
Add AM_MISSING_PROG

The AM_MISSING_PROG macro was not present.
Fix highlighting bug in macro arguments

Previously, the TO-ARGS-* contexts ended if the next character was a
comma or closing parenthesis; but they need to extend from the beginning
comma to the closing parenthesis so that they contain the next TO-ARGS-*
subcontext instead of matching themselves more than once.

e.g. if AC_SOMETHING was a "MMSS" macro

AC_SOMETHING([foo], [bar], [false], [true])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ARGS-MMSS
             ^^^^^ ARG-M
                  ^^^^^^^ TO-ARGS-MSS
                    ^^^^^ ARG-M
                         ^^^^^^^^^ TO-ARGS-MSS
                           ^^^^^^^ ARG-M
                                  ^^^^^^^^ TO-ARGS-MSS
                                    ^^^^^^ ARG-M

should be

AC_SOMETHING([foo], [bar], [false], [true])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ARGS-MMSS
             ^^^^^ ARG-M
                  ^^^^^^^^^^^^^^^^^^^^^^^^ TO-ARGS-MSS
                    ^^^^^ ARG-M
                         ^^^^^^^^^^^^^^^^^ TO-ARGS-SS
                           ^^^^^^^ ARG-S
                                  ^^^^^^^^ TO-ARGS-S
                                    ^^^^^^ ARG-S

This fixed it so that extra (illegal) arguments are now highlighted as
such. Also, previously, shell (S) or pure M4 (M) arguments could be
highlighted wrongly as shown in the diagram above.