Calculate median SLA stats over sampling interval.

Bugs closed: AURORA-733

Reviewed at https://reviews.apache.org/r/26002/
Implementing quota checking for async job updates.

Bugs closed: AURORA-686

Reviewed at https://reviews.apache.org/r/25812/
Expose in progress and recently completed updates in UI

Bugs closed: AURORA-745

Reviewed at https://reviews.apache.org/r/25963/
When creating an update, store only the delta between the initial and desired states.

Bugs closed: AURORA-718

Reviewed at https://reviews.apache.org/r/25969/
Fix extra constructor arg causing build break.

Reviewed at https://reviews.apache.org/r/26024/
Skip past irrelevant jobs when running cron show command.

Bugs closed: AURORA-753

Reviewed at https://reviews.apache.org/r/26015/
Fix checkstyle broken by rb/26015.

Testing Done:
My commit made it in.

Reviewed at https://reviews.apache.org/r/26043/
Adding support for transient storage errors.

Bugs closed: AURORA-187

Reviewed at https://reviews.apache.org/r/25970/
Run python style checks in jenkins.

Reviewed at https://reviews.apache.org/r/26044/
Fix breadcrumb and page titles in UI.

Reviewed at https://reviews.apache.org/r/26048/
Prevent uncaught exceptions from straight up killing the executor.