Show unified timeline view of logs

[criccomini]

The current log view for Zopkio shows a list of files that get aggregated to the driver machine. I can pick and choose which file to look at from there. This view is suboptimal. What I really want is a single view that merges all logs into a single timeline, sorted by machine timestamp. I think this would make it much easier to debug issues.

For example, instead of having:

test1.log
test2.log
zookeeper.log
kafka.log

What I'd rather have is:

[12:45] test1 log line
[12:46] test1 log line
[12:47] zookeeper log line
[12:48] zookeeper log line
[12:48] test1 log line
[12:50] kafka log line
[12:54] test2 log line
[13:37] kafka log line

This would allow me to figure out when failures on one machine/log file relate to failures on another.

[criccomini]

What would be really cool is to show this log broken down by test. So, a view like:

file:///private/tmp/samza-tests/zopkio_20150222_153852/reports/tests_20150222_153852/resources/single%20execution/test_container_performance_report.html

Might have the log snippet for all logs between the start and end of the test.

[criccomini]

It would also be useful to allow users to filter the files that are shown in the merged view. For example, I might not want to see the GC logs, which could be quite verbose.