bug in selecting html attributes for "print_select" function.

There was a bug in how a select string is converted into an array. There is a simplistic function "_hex_select_string_to_array" that does this but it didn't take into account white spaces.

For example, doing the following from a template would not work.

print_select($html_elements, "title > inline_html#element_open")

But this would.

print_select($html_elements, "title>inline_html#element_open")

The space between "title", ">" and "inline_html" would break it. The patch fixes this so both forms work just the same.