(bug 44024) ObjectCache changes break XCache 3.x support

Changes in the 1.20.x branch altered the add method to check for the return value of get against
false.  Xcache 3.x returns NULL for unset values and so this check was erroneously determining that
all values are set when they were not.

This was causing basic ObjectCache usage to fail.

Change-Id: I0975e5c6a60c2813dc2d02aca84245807b8fb828
(cherry picked from commit 0072e0efeb8591a7761b3d573f8b71ef97fb96ec)
Made SSL validation in Curl HTTP requests the default.

Changed the default value for CURLOPT_SSL_VERIFYHOST
to 2 rather than true. This makes sure that hostname
validation occurs.

Change-Id: Ia6535f1090627ef2def360bda37c22bff10c7f31
(cherry picked from commit 5c8d6fa60f521073136012f67e66bdb72010e720)
Backport compatible message changes from master.

Change-Id: I9e3c03c3d6178a85169765abb04e8e9ca910f409
Backport compatible message changes from master.

Change-Id: I4c67e4f3e37ef99d594f3d191ff1af81428b9d53
Remove unneeded translations

Falls back to 'bho' where the translation are.

Change-Id: Idcaa1fdb252f260f94166abd433a4fbf5d89f6f1
Localisation updates from http://translatewiki.net.

Change-Id: I92d1a5b7e111997e8b9cb5d965d884897069eae0
composer.json for REL1_20 branch

https://packagist.org/packages/mediawiki/core

Change-Id: I7eb00b98a0e3574b2709c6d0e8cec9df9b661a4a
Merge branch 'REL1_20' of https://gerrit.wikimedia.org/r/p/mediawiki/core into REL1_20