Test shortcode's order according to frequency

The unit test for cangjie_get_characters_by_shortcode() was testing
against order happens to be the result of the previous build process.
It should, however, test against the order of frequency.
Order the query results

Added "ORDER BY frequency ASC" to the end of query strings used
in cangjie_new_characters and cangjie_new_characters_shortcode.

Since the linked-list is built with an prepend mechanism, the results
will be of reverse order of the query. Which will effectively gives
a "ORDER BY frequency DESC" result.

This commit fixes the default order of results, but it does not provide
a way for user to freely specify sorting logic.

Partially fulfilled enhancement #64.