Shows totals for shuffle data and CPU time in Stage, homepage overviews including active time
Split Shuffle Activity overview column for read/write
Displys shuffle read/write only if exists, wraps if statements, trims old vals, grabs current time once
Made metrics Option instead of Some, fixed NullPointerException
Current time called once with value now
Moved val now to render
Cleaned up code based on pwendell's suggestions
Fixed outdated bugs
Alphabetized imports
Merge pull request #735 from karenfeng/ui-807

Totals for shuffle data and CPU time