…ompletion state; use mock spark UI

…ault = 60; document

…om string to case class

… metrics used to track load & time —and for testing

… comments & stylecheck

…viction is taking place

…this triggers callbacs in the cache

… to keep scalastyle happy

…cking up any changes

…t being saved

…llelize().count() call, so the FS history provider isn't seeing an update, etc, etc.

…o scans through modified files to verify this takes.

…LoggingListener attempts to do so afterwards, swallowing exceptions raised

… its a race condition between probe time and the scanner thread -if the initial load is after the file update but before the scanner thread has looked @ the file, the file isn't detected as updated. The provider has to return the actual file timestamp of its choice for use in update checks, not the time that the initial load took place

…ore time details, but I'm about to move the fshistory off time and into a generic "attempt version" counter which will be compared on the probe. If an update has happened, this will know

…r and equality check

-verifies the app is initially listed iin the ?showIncomplete=true HTML page
-executes repeated jobs with extending sleeps between them, to see if that cause problems
-stops the app
-verifies that FsHistoryProvider.getListing() returns an app that is now complete
-verifies that the app listing moves from the incomplete list in HTML page to completed

this verifies that the change from incomplete->complete is picked up all the way to the UI.

… other details (monitoring.md wasn't up to date with the incomplete apps feature)

… from the loadedUI state and probes; makes for a leaner API

…rectly: no more cache and relay of state

…ionCache

…dentified: SPARK-10873's switch to dynamic tables means scans of static HTML fails

…has issues