Prepare 3.1.5 release
Correct duplicated update queries
Prepare master for development
 $ Updating installation lang files: ru-RU, sv-SE
 # [#31297] Content language manager missing drag drop ordering. Thanks
Nguyen Huu Hien
(Fix #1456)(Fix #1415)
 # [#27476] Menu types view not sorted alphabetically. Thanks Lao Neo
(Fix #1498)(Fix #1511)
 # [#31586] Typo in model
administrator/components/com_content/models/article.php. Thanks Volkmar
Schlothauer and Brian Teeman
(Fix #1598)
 # [#31536] Adding filters in backend Installation Discover view for
3.x. Thanks Gunjan Patel
(Fix #1572)
 # [#31564] Missing images in sample data categories. Thanks Roland
Dalmulder
(Fix #1592)
 #$ [#30793] Spelling error in the title of the Edit Article Category
screen
 #$ [#31357] Add the Default parameter to the colour options for the
templates to the desc strings. Thanks Tobias Zulauf
(Fix #1426)
 # [#31411] Show Offline image only if it exists. Thanks Tobias Zulauf
(Fix #1453)
 # [#31360] The site is offline but anyhow the error page will show
(e.g. at a 404 error). Thanks Mihail Irintchev
(Fix #1521)
 $ [#31356] Media manager option desc. Thanks Tobias Zulauf.
(Fix #1424)
 # [#31440] Cleanup & fixes for the admin menu. Thanks Sander Potjer
(Fix #1509)
 # [#31387] Button class missing for export banner tracks. Thanks Brian
Teeman
(Fix #1442)
 # [#31554] Module manager allows positions with trailing spaces. Thanks
Richard McDaniel
(Fix #1581)
 # [#31632] Small data type fix in phpdoc. Thanks Gunjan Patel
(Fix #1631)
# [#31384] Hathor - Modal broken. Thanks cata castillo (Fix #1457)
 # [#30806] Incorrect database type in the Statistics site module.
Thanks Brian Teeman
(Fix #1120)