Attempt to lower the number of resources consumed while running tests

I keep having too many resource issues while running tests, so bit the bullet and try to cleanup a lot. We no longer consume 2k+ threads, but there is still a lot more work to do.

After this PR, we peak around 240 threads (used to be 2-3k)
For others to enable.  Can remove.
On Oct 18, 2014 4:20 PM, "Haoyuan Li" <notifications@github.com> wrote:

> In core/pom.xml:
>
> > @@ -358,6 +358,8 @@
> >          <artifactId>maven-surefire-plugin</artifactId>
> >          <version>2.14</version>
> >          <configuration>
> > +          <!-- use to enable flight recorder -->
> > +          <!-- <argLine>-Dufs=${ufs} -XX:+UnlockCommercialFeatures -XX:+FlightRecorder</argLine> -->
>
> Is this WIP? Why leave comments here?
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/amplab/tachyon/pull/474/files#r19056838>.
>