MDL-17094 Automatic language update can be disabled via $CFG->skiplangupgrade settings. Merged from MOODLE_19_STABLE

MDL-13927, MDL-13938 indicate missing parent languages and allow multiselection when importing langs; merged from MOODLE_19_STABLE

MDL-12698, MDL-12569 - componentlib & langimport improvements and fixes; merged from MOODLE_19_STABLE

download magic. Convert to use download_file_contents() for more
robust downloads. And also add a more helpful error message while i'm
at it.
merged from MOODLE_19_STABLE

MDL-9563 Improve refreshing of langcache, detect permission problems

merged from MOODLE_18_STABLE

MDL-8758 - Corrected the packagezip -> package.zip typo in 3 locations (2 in admin/langimport.php and 1 in install.php). The notification about allow_url_fopen has already been added to the default lang/en_utf8/error.php string.

Merged from MOODLE_18_STABLE:
Fix for MDL-8653:
When updating languages through a proxy, skip to the end of the HTTP headers
as defined by RFC 1945 instead of skipping exactly 12 lines of chaff.

Credit for patch 100% to Dan Poltawski.

Merging from MOODLE_18_STABLE:
Updating local language packs was breaking XHTML in the "results" screen.

Now the list of downloadable langs (when no fopen is available) doesn't break XML. Related to MDL-7861

accessibility cleanup in langimport.php - original patch by Nick Freear MDL-7438 + whitespace and old code cleanup

th should be used only for data tables

deglobalization of $ADMIN; merged admin/adminlib.php into lib/adminlib.php; fixed includes and some other minor fixes

(http://moodle.org/bugs/bug.php?op=show&bugid=4924)