Capture and store user requests to the Synoptic web app

The deployed instance of Synoptic should capture user log processing requests 
so that we can then study the captured data to better understand what users 
care about, and what aspects of the application they find difficult. An 
important consideration is to provide a means to disable this functionality in 
the released version of Synoptic (which is intended to run locally on a user's 
machine).

The two basic inputs that we want to capture are:
- Log input
- Regular expressions inputs (parsing/splitting/partitioning)

Some other, more dynamic, behaviors that we might want to capture include:
- Time spent on each tab
- Changes to regular expressions over the course of a user session
- Use of the invariants tab -- what parts of the tab do users interact with 
(e.g., do they ever mouse over the invariant graphic?)
- Use of the model tab -- what parts of the tab do users interact with (e.g., 
do they ever click model nodes?)

For storing the captured data we can use Derby, a relation DB implemented in 
Java:
http://db.apache.org/derby/

Original issue reported on code.google.com by bestchai on 18 Nov 2011 at 4:16

Blocked on: #148, #216

mgijsberti / synoptic

Capture and store user requests to the Synoptic web app #165