ETA with icons

[linzuzeng]

1. A set of built-in icons will be included in ETA GUI.
2. There will be a new section in ETA file format that maps the name of the blob to icons.
3. The drawing panel will read the icon map and uses the corresponding icons for each blob.
4. A naive scanning method will be applied in the coding panel to automatically change the icon map when the code is being typed.
5. A partial update system for graphics will be established to connect 3 and 4 so that user can see the updates of icon when typing the code. The partial update is required so that we only update the influenced part of the graph without stucking the GUI
6. The icon map should be updated accordingly when the blob is renamed ,or removed.

[linzuzeng]

How about giving icons for Virtual Instruments instead of the circles in the Virtual Instruments?
We can make icons for correlation, acquision devices, delay line, etc...

It can be seen clearly on the main screen what every VI is doing.