MDL-23068 removing obsolete $result and removing empty upgrade files that would be probably never used at all + minor cleanup/fixing

MDL-22950 adding new component column to the files table, unfortunately this change requires changes in all 2.0dev code, please review all custom code that was already upgraded to 2.0; fixing multiple problems and regressions in mod/assignment

New string is available. Use get_string('labelsep', 'langconfig') to be used
as a separator between a label and the labelled text. If you want to
produce <label> HTML element, you may be interested in the new
html_writer::label() method. Simple selects and URL selects now use it.

There are bambillion places where ': ' is hardcoded as a separator. I do
not think we have to fix them manually now (and mass search and replace
would be tricky) but everybody should stop adding new.

Do not abuse 'labelsep' for any other purposes. Note that it may not be
colon in some languages or sites.

MDL-22609 undoing directory variables magic from last commit, keeping just the userid-->submissionid itemid change

message MDL-23051 made the contact list display properly after removing a contact from within the contact search results.

javascript MDL-22920 Added support for CSS images within the new module code and added missing requirement

registration MDL-22964 check if xmlrpc is enabled on the registration pages, publication pages and community block page.

Strips _utf8 suffix for remote users roaming from Moodle 1.x sites.
Checks that the preferred language is actually installed, uses the site
default otherwise.

Fixed SQL, strings usage, CSS class. In the future, we can distinguish
information displayed for the owner and for the others, as well as what
to display in the course profile (user/view.php) and public profile
(user/profile.php).

mod/assignment MDL-22609 Checking in Aparup's patch fixing the file upgrade (itemid now is submission->id, not user->id).  Also fixed some buggy uses of $OUTPUT->notification in uploadsingle->upload()  (redirect works better)