Added range options to the float validation filter
php_filter_int (called via the constant FILTER_VALIDATE_INT) has the options min_range
and max_range. they allow the user to not only test if a value is a double but also if
the value is inside a specific range. php_filter_float (called via the constant
FILTER_VALIDATE_FLOAT) didn't provide this yet, making validation of numeric but
not-only-int values more complicated for the user.
this commits implements the options min_range and max_range for the function
php_filter_float to fix this inconsistency.