zend_parse_parameters: allow ! for non pointers

This commit allows getting information about whether a certain value
was a NULL value by using the ! modifier together with the l/L, d and
b.

Example:
long l;
zend_bool is_null;
zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l!", &l, &is_null)

For the specifiers l/L, d and b, NULL values are reported as 0, 0., or
false. But sometimes one wants to distinguish NULL from those other
values -- for instance, to give NULL the same effect as the argument
not having been passed.

The usual way this problem is handled is by fetching the parameter
with 'z' or 'Z', check if it is NULL and if not use
convert_to_long_ex()/convert_to_double_ex(), etc. Unfortunately, this
is not equivalent. convert_to_long_ex() does a cast, while zpp() is
stricter. For instance, zpp will not accept 'foo' for a long argument,
and it will emit a notice when encountering '5foo'.

In fact, the only way to otherwise zpp semantics (without duplicating
its logic) is to fetch the raw zval from the stack and check whether
it's NULL (with zpp itself or its relatives) and then run zpp again.
That is not an elegant solution.
Expose zend_parse_arg() as zend_parse_parameter()

Sometimes, one wants to accept several types for a given parameter. zpp
has special functionality for detecting the NULL type, since the NULL
type is frequently used to skip parameters.

However, supporting several types is otherwise very tedious. There are
many cases where this situation arises -- for instance one may want
to accept an arbitrary number of integer and expect them in an array,
but allow a bare integer too; one may want to accept something that
will be used as an array key (which can be either and int or a string);
one may want to accept integer and double numbers. A search for IS_LONG
reveals many situations where this need arises.

The usual solution is to fetch the argument with 'z'/'Z', check its
type, and then convert the argument, e.g. with convert_to_long_ex().
As explain in the last commit, this has different behavior and
generates inconsistency.

Another -- even more flawed strategy --, is to try zpp with a specific
format, forcing it quiet, and if it fails retrying with another form.
But because zpp changes the arguments directly in the stack (for
instance, using "l" converts the zval in the stack to IS_LONG), the
arguments may look different after the first zpp, leaving subtle bugs.

This commit also allows more complex scenarios, for instance where the
expected type of one parameter depends on other parameters.
Merge branch 'PHP-5.5'
Cleanup NEWS
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5'
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5'
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5'
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5'
Deprecate ext/mysql.

Per https://wiki.php.net/rfc/mysql_deprecation, connecting to a MySQL database
via ext/mysql now generates an E_DEPRECATED error. This commit includes the
minimal EXPECTF updates required for the test suite to pass: it may be
preferable to refactor some of the tests to suppress deprecation errors in
situations where no other error is expected from mysql_[p]connect(), but I'm
not enough of a MySQL expert to want to get my hands that dirty in a long
standing test suite.
Merge branch 'PHP-5.5'

* PHP-5.5:
  Deprecate ext/mysql.
Tinker with the wording of the MySQL deprecation news post.

I know that in general NEWS is a very punchy "this is what happened" log, but
Chris e-mailed me off-list to ask if it could be added to avoid any FUD — this
merely brings the NEWS post into line with UPGRADING, the migration guide, and
every other piece of advice we're giving out.

I also forgot to add the RFC URL last night, so added that.
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  Alter php_json_decode_ex() to respect JSON_BIGINT_AS_STRING for bare numbers.
Merge branch 'PHP-5.5'
- generators API exported for extensions
- improved RETURN sequence to avoid redundant check if op_array is a generator
Merge branch 'PHP-5.5'

* PHP-5.5:
  - generators API exported for extensions - improved RETURN sequence to avoid redundant check if op_array is a generator
Fixed Bug #63738 unpack: back result with Z format

Fix result for empty string.
Same output as perl
perl -e 'print unpack("Z2","\0\0");' => ""
perl -e 'print unpack("Z2","A\0");'  => "A"
perl -e 'print unpack("Z2","AB\0");' => "AB"
perl -e 'print unpack("Z2","ABC\0");'=> "AB"