Merge pull request #913 from sanger/next_release

Release-5.26.0
Update Jruby-rack and force use of Jruby::Rack::ErrorApp
Remove features and edit tags controller
Adds migration to fix the submission visualization problem for
very old submissions.
Modifies view to give an informative message related with this submissions
JSON encode strings before passing to stream

Strings were being passed to the stream as is, so characters
like double quotes weren't being escaped. We just use to_json
to help here.
Merge pull request #914 from JamesGlover/return_503_when_busy

Update Jruby-rack and force use of Jruby::Rack::ErrorApp
Merge pull request #915 from JamesGlover/cleanup_unused_features

Remove features and edit tags controller
Merge updated Gem versions
Merge pull request #918 from JamesGlover/fix_json_encoding_bug

Fix json encoding bug
Fixes problem while updating request_options because of
the serialization not being performed with update_all
Fixes rollback migration
Merge pull request #917 from emrojo/74678262_bug_looking_old_submissions

74678262_bug_looking_old_submissions