Implemented issue #998: Added support for IPv6

- Rewrote the xdebug_create_socket function so that it also supports
creating sockets for IPv6 addresses.
- Wrote a couple of tests that test both IPv4 and IPv6 connectivity.
- Added some functions to the DebugClient (some refactoring to make it
more extendable).
- Created a DebugClientIPv6 class that extends from DebugClient. This
communicates with Xdebug over IPv6.
Issue #998: Fixed code formatting and comments

- Fixed the code so that it (hopefully) complies to existing coding
standards.
- Reordered some of the include and define statements.
- Added comments to the code explaining what is done.
Issue #998: Fixed typo in comment
Implemented issue #998: Added support for IPv6

- Rewrote the xdebug_create_socket function so that it also supports
creating sockets for IPv6 addresses.
- Wrote a couple of tests that test both IPv4 and IPv6 connectivity.
- Added some functions to the DebugClient (some refactoring to make it
more extendable).
- Created a DebugClientIPv6 class that extends from DebugClient. This
communicates with Xdebug over IPv6.
Merging (hopefully, GitHub is not my friend) from master to issue998-ipv6.
Added the non-blocking method of connecting to the client.

This should work. I could only test it on our Ubuntu server, but it
works great over both IPv4 and IPv6 as far as I have been able to test.
Moved and renamed SOCK_TIMEOUT

Moved the SOCK_TIMEOUT definition from xdebug_com.c to xdebug_com.h and
renamed it to SOCK_TIMEOUT_ERR instead.
Implemented issue #998: Added support for IPv6

- Rewrote the xdebug_create_socket function so that it also supports
creating sockets for IPv6 addresses.
- Wrote a couple of tests that test both IPv4 and IPv6 connectivity.
- Added some functions to the DebugClient (some refactoring to make it
more extendable).
- Created a DebugClientIPv6 class that extends from DebugClient. This
communicates with Xdebug over IPv6.
Merge branch 'issue998-ipv6' of github.com:vanhanit/xdebug into issue998-ipv6

Conflicts:
	tests/bug00998-ipv4.phpt
	tests/bug00998-ipv6.phpt
	tests/dbgp/dbgpclient.php
	xdebug_com.h
Back to dev on the new 2.3 branch.
Fixed bug #834: Regenerate example xdebug.ini.
Fixed test case.
Added a new test case.
Added some more files to the ignore list.
Fixed PHP-932: Added an error message in case the remote debug log couldn't be opened.
Fixed bug #863: Support xdebug.overload_var_dump through ini_set().
Added compatibility with other extensions modifying zend_error_cb
Added support for serialized "collect_params".

This is option 5 to collect_params, and when enabled will also add serialized
return values into the machine readable traces as an extra line with type "R".
Fixed existing tests to the new format version number.
Solve the issue with closures by hijacking the serialize handler.