change to jsp file to add a  worker page

Add a worker page and remove worker infos from general page
update servlets

update servlet for general page and worker page
Revert "update servlets"

This reverts commit 0f21a350ecef15d03699b7d5123de7af18f6d40d.
Revert "Revert "update servlets""

This reverts commit 53063c556d95136023de5226d7adf17caf562ddf.
Revert "Revert "Revert "update servlets"""

This reverts commit dd3a6debe851af2e9bb7afdb3620ad6cafce3f75.
Revert "change to jsp file to add a  worker page"

This reverts commit 7f4948635758a31e00797c89b67e8567e6d10643.
change to jsp file to add worker page

add a workers page and remove the worker info from general page
update servlets

update servlets to support new web page
update overview page

change the overview page back to have "Tachyon Summary" and "Cluster
Usage Summary" in the same row.
Refactor sorting

Refactor sorting code in WebInterfaceWorkersServlet.java
Merge pull request #423 from PasaLab/UI-addworkerpage

[TACHYON-138]