- Implements the ability to rename ZEND_INTERNAL_FUNCTION functions while keeping track of the original functions.
- Adds method restore_internal_functions() to restore all renamed functions to their original functions.
- Activated rename_internal_function.phpt, added restore_internal_functions.phpt
- Replaced space indent with tab / Comment fixes
- Use globals-> over THG() in php_test_helpers_init_globals
- Moved internals of PHP_FUNCTION(restore_internal_functions) to regular C function and are now calling that
- Resolve segfault on shutdown.
- Fix whitespace.
Improve HashTable handling for renamed functions.

One test still fails since it accesses free'd data, so this needs
some more review.
Move cleanup out of the loop to avoid accessing free'd data.

a simple test case like

    <?php
    function my_printf($p) {}
    rename_function('printf', 'foobar');

Still gives leaks as my_printf() isn't cleaned up. Not sure whether this
is caused by this patch. Leaks:

    [Sun Apr 17 02:21:16 2011]  Script:
    'tests/rename_internal_function.php'
    Zend/zend_language_scanner.l(1695) :  Freeing 0x08843D9C (10 bytes),
    script=tests/rename_internal_function.php
    [Sun Apr 17 02:21:16 2011]  Script:
    'tests/rename_internal_function.php'
    /home/johannes/src/php/src/php/php-src/branches/PHP_5_3/Zend/zend_opcode.c(63)
    :  Freeing 0x08843E0C (4 bytes),
    script=tests/rename_internal_function.php
    [Sun Apr 17 02:21:16 2011]  Script:
    'tests/rename_internal_function.php'
    /home/johannes/src/php/src/php/php-src/branches/PHP_5_3/Zend/zend_opcode.c(380)
    :  Freeing 0x08843E3C (152 bytes),
    script=tests/rename_internal_function.php
    [Sun Apr 17 02:21:16 2011]  Script:
    'tests/rename_internal_function.php'
    Zend/zend_language_scanner.l(1672) :  Freeing 0x08845310 (2 bytes),
    script=tests/rename_internal_function.php
    [Sun Apr 17 02:21:16 2011]  Script:
    'tests/rename_internal_function.php'
    /home/johannes/src/php/src/php/php-src/branches/PHP_5_3/Zend/zend_compile.c(282)
    :  Freeing 0x08845340 (192 bytes),
    script=tests/rename_internal_function.php
    [Sun Apr 17 02:21:16 2011]  Script:
    'tests/rename_internal_function.php'
    /home/johannes/src/php/src/php/php-src/branches/PHP_5_3/Zend/zend_compile.c(1511)
    :  Freeing 0x0884542C (24 bytes),
    script=tests/rename_internal_function.php
    [Sun Apr 17 02:21:16 2011]  Script:
    'tests/rename_internal_function.php'
    /home/johannes/src/php/src/php/php-src/branches/PHP_5_3/Zend/zend_compile.c(1513)
    :  Freeing 0x08845470 (2 bytes),
    script=tests/rename_internal_function.php
    === Total 7 memory leaks detected ===
Merge commit 'b17f4cd1c2e738195d38f91e779bb0ec59d779d1' into merge_johannes

Conflicts:
	test_helpers.c