MDL-46538 theme_base/theme_bootstrapbase: Removed incorrect RTL CSS mark-up.
MDL-46536: OAuth signature fails with inconsistent new lines

When the LTI intro contains a single \n or
\r newline character then the OAuth signature
fails.  All newlines should be \r\n
MDL-46552 session: add support for multiple servers in memcached session driver
MDL-46711 session: add support for multiple servers to memcache session driver

Includes proper definition of object properties which fixes handling of timout default.
MDL-46775: Fix call to unavailable function when loading an invalid JS file
MDL-41513 mod_quiz: Scrollbar not working in Javascript Security Popup Quiz window in Chrome
MDL-46791 question: fixed incorrect 5th param for tag_set()
MDL-46796 caching: Fix missing property error for memcache(d)
MDL-46051 mod_lti: Fixing errors in unknown_service_api_called class

Also adding unit tests.
MDL-46051 mod_lti: Not enough data passed to lti_extend_lti_services
MDL-46772 core: html_writer::table should respect tr attributes
MDL-18014 Atto: Autosave text every N seconds.
MDL-18014 Atto: Add notification support to Atto.
MDL-18014 Atto autosave: Change default autosave frequency to 60 seconds
MDL-18014 Atto autosave: Show warning when the server cannot be contacted for autosave.
MDL-18014 Atto autosave: Correct detection of autosaving error when session expired
MDL-18014 Atto: Reset auto save frequency to 60 seconds.
MDL-18014 Atto autosave: Fix coding style issues
MDL-18014 Atto: Add a notification when text is autosaved.
MDL-18014 Atto: Make the autosave frequency configurable