Update plugins/mobile to version 1.6

plugins/mobile/CHANGES.txt

plugins/mobile/README.txt

plugins/mobile/desktop.php

plugins/mobile/desktop_unset.php

plugins/mobile/graphics/elgg_toolbar_logo.gif

plugins/mobile/graphics/toptoolbar_background.gif

plugins/mobile/index.php

plugins/mobile/languages/en.php

plugins/mobile/manifest.xml

plugins/mobile/start.php

plugins/mobile/version.txt

plugins/mobile/views/default/mobile/metatags.php

plugins/mobile/views/default/settings/mobile/edit.php

plugins/mobile/views/mobile/account/forms/login.php

plugins/mobile/views/mobile/account/forms/register.php

plugins/mobile/views/mobile/annotation/annotate.php

plugins/mobile/views/mobile/annotation/generic_comment.php

plugins/mobile/views/mobile/blog/categorylist.php

plugins/mobile/views/mobile/blog/css.php

plugins/mobile/views/mobile/blog/forms/edit.php