Add y-axis domain controls.

[samussiah]

Add y-axis domain controls.

[emmorris]

Moving back to development since there were some suggested changes found during code review.

[jwildfire]

Test notes:

• Three new controls appear:
  • one that controls the lower limit of the y-axis
  • one that controls the upper limit of the y-axis
  • one that resets the y-axis to the minimum and maximum values in the data
• Typing in a number into either the lower limit or upper limit control updates the y-axis domain accordingly.
• The lower limit cannot be equal to or greater than the upper limit.
• The upper limit cannot be equal to or less than the lower limit.
• The reset button resets the y-axis to the minimum and maximum values in the data.

[dschwentker]

Tested and passed in all browsers. Lower limit, upper limit, and Reset limits button all work as expected.