Adding Digital Time Series

[nonrice]

Other changes:

• Changing some naming to differentiate between analog/digital
• Changing some naming in order to be consistent with JKQTPlotter terminology
  • So a "plot" is what the user sees, i.e. the rectangular region with things inside
  • A "graph" is a single element within that region. Currently there are Analog graphs and digital graphs.
• Add a click to select graph feature (currently only works with the analog graphs since expected behavior might be ambiguous if digital graphs were included)
• Add hide show button for graphs
• Fix to disable grabcut iteration button before the rectangle is drawn.

[nonrice]

As usual CI passed for my fork

[nonrice]