use args in cache_key

**Migrated issue, originally created by Anonymous**

use function args in cache_key is very usefull:


    <%def name="foo(id)" cached="True" cache_key="foo_${id}">
    ${id}
    </%def>

----------------------------------------
Attachments: [args_cache_key.patch](../wiki/imported_issue_attachments/78/args_cache_key.patch)

