Expand all and unhide all functionality

[bestchai]

Right now, if a user wants to expand all events, they would have to do it individually for each sequence and similarly, for unhiding hosts, they would have to click on each host individually. It would be helpful to have one area of control where all events could be expanded and all hosts could be unhidden.

In relation to Issue 133, it might also be helpful to have a particular sequence of events automatically expanded if it contains a match for the current query.

[Issue created by pattypcw: 2015-07-16]