Description:
------------
libedit (tested with version 3.0) provides "callback" functions, but php doesn't detects/provides them.


The attached patched 
- add detection for "rl_callback_read_char" when build with "--with-readline"
- add detection for "rl_on_new_line" which is only available when build "--with-readline"

Exemple from http://www.php.net/readline_callback_handler_install works.


Test script:
---------------
php  -r 'print_r(get_extension_funcs("readline"));'

Expected result:
----------------
Array
(
    [0] => readline
    [1] => readline_info
    [2] => readline_add_history
    [3] => readline_clear_history
    [4] => readline_read_history
    [5] => readline_write_history
    [6] => readline_completion_function
    [7] => readline_callback_handler_install
    [8] => readline_callback_read_char
    [9] => readline_callback_handler_remove
    [10] => readline_redisplay
)


Actual result:
--------------
Array
(
    [0] => readline
    [1] => readline_info
    [2] => readline_add_history
    [3] => readline_clear_history
    [4] => readline_read_history
    [5] => readline_write_history
    [6] => readline_completion_function
)