Add fetch() support to MatrixState

[jcchuang]

Add javascript code to read data and state information from server (via cgi-bin/getEntry.py) whenever the attribute "dataID" is changed".

In MatrixState.js:

• Defining the appropriate MatrisState.prototype.fetch function.

In index.html

• Currently, the webpage loads states/data from server via an ajax call and then initializing the matrix by calling the functions setEntries() or setMatrix(). The webpage should now only need to initialize a StateMatrix object and setting its dataID attribute.

Implement issue #9 prior to this task.

[jcchuang]

Implemented in ab07ae3