course publish MDL-19315 fix improper use of moodle form (=> require values go now through validation)

old admin blocks MDL-22475 Goodbye admin and admin_tree.  You were good to us.  But now we have Settings.

thanks to Jay Knight for the patch

The results of merged en + en_local + parentlang + parentlang_local +
lang + lang_local are now saved into disk cache in dataroot/cache/lang/.
The number of get_string() calls, and number of mem cache and disk cache
hits are part of performance logging.
Disk cache must be removed whenever the language packs or their local
customizations are deleted. Disk cache is rebuilt automatically.

MDL-14534 - now you can remove 'Not selected' option

    - fixed user styles in base theme
    - added new divs for better control on user profile and user index pages
    - reduced data on course user profiles down to minimum
    - removed user/tabs.php completely and all uses of it
    - changed default user icon pix to something very bland (bye bye smiley cake)

MDL-14534 - now you can remove 'Not selected' option

print_courses() produced PHP notice (Trying to get property of
non-object) and generated an invalid button to create a new course in this
case: (1) Passed paramater $category is 0 to display all categores (as in
case of home page, for example) and (2) get_child_categories(0) returns
more than one record. In such case, $categories is still a plain
integer, does not contain ->id property and the called /course/edit.php
exits with error.
This patch uses $CFG->defaultrequestcategory as category id in this
case.

Adding some strings

Formatting the code

MDL-19168, dropbox repository plugin for moodle, and oauth support for filepicker. dropbox plugin has a known bug: cannot access folders or files with space, using urlencode to encode filepath is not helping, needs to contact dropbox team to find workaround

Fixing this problem.