Added mail logging functionality that allows logging of mail sent via
mail() function

THe logging functionality is disabled by default but can be enabled on a
per-directory or globaly via 2 INI settings.

The mail.log directive allows you to specify the file where each call to
mail() will be logged. The log file will contain the path and line # of the
calling script in addition to all of the headers indicated by the user.

The mail.add_x_header directive will introduce a X-PHP-Originating-Script
header that will contain the file name (no path) of the calling script and
the uid of the script. This combination should be sufficient for the admin
to locate the sending script.

After the sigsetjmp change, this is patch #2 in an effort to get some
sanity restored to signal handling in PHP.

This patch does two things.  First, it makes it possible to reset the
timeout without resetting the signal handlers.  This is important for
cases where an extension may have deferred signals in its MINIT in order
to implement critical sections. It also lays the groundwork for cleaning
up our signal handling and perhaps eventually implementing our own
signal deferring mechanism so we can have true critical sections.

The second thing this does is to make it possible to terminate the current
child process (only for Apache1 at the moment) on a timeout.  There are
a number of extensions that are unhappy about being longjmp'ed out of
and when this happens on a timeout they are left in an inconsistent state.
By turning on exit_on_timeout you can now force the process to terminate
on a timeout which will clean up any hanging locks and/or memory left
hanging after the longjmp.

# if not set (default), variables_order still is used
# request_order accepts G,P and C

- Added ".htaccess" style user-defined php.ini files support for
  CGI/FastCGI.
- Added support for special [PATH=/opt/httpd/www.example.com/] sections
  in php.ini. All directives set in these sections will not be able to be
  overridden in user-defined ini-files or during runtime in the specified
  path.

- Improved php.ini handling:
  . Added better error reporting for syntax errors in php.ini files
  . Allowed "ini-variables" to be used almost everywhere ini php.ini files
  . Allowed using alphanumeric/variable indexes in "array" ini options
  . Fixed get_cfg_var() to be able to return "array" ini options

- Fixed bug #27372 (parse error loading browscap.ini at apache startup)
- Fixed bug #42069 (parse_ini_file() allows using some non-alpha numeric
  characters)