user_access should not use user-interface-string as permission

the function user_access() uses one string: as permission-key and as user-interface string.
This is both dangerous, and inflexible. Dangerous because a wrong translation can open up critical permissions to the wide world. Inflexible because it limits what one can send to the screen: for example this flexinode (patch)issue forces us to make permissions such as 'create flexinode_1 content', instead of the much friendlier 'create blog content'. And please: do not use this thread to prove that the example-issue above can be solved without modifying core: it is only an example!

The solution is simple: we need to fix the design flaw 'permission key === interface string'. The easiest, and IMHO best solution is to pull apart the key and the string:
A permission registration would then be:

 $perms['create_'. $name .'_content'] = t('Create new %name', node_get_name($name));
 $perms['edit_user_data'] = t('Edit user data');