Read /proc filesystem to log CPU/Network/Disk utilization.
Added fetch wait time and fraction waiting to UI
Fixed compile errors after rebase
Added precise logging for fetch time.

This commit adds functionality to the job logger to log exactly
when each fetch started and finished, how long it took to read
the fetched data off of the machine where it was fetched from,
how big each individual fetch was, and exactly when the
application requested shuffled data.
Added missing plus sign to fix log output
Bug fix: actually write/read readTime from buffer
Add shuffle write time to job logger
Updated disk read time to use nanoseconds
Added GC and deserialize time to JobLogger
Removed lengthy blockRequestTimes output
Added input size and read time.

This commit adds a new metric in TaskMetrics to record
the input size and read time when data is read from the BlockManager,
from HDFS, or from a parallelized collection, and displays this
information in the UI.