Empty hydrophobicity scale defaults to last value, but box remains empty after tabbing out of entry box and sliders out-of-sync

[mebh]

Example case:

1. Go to the hydrophobicity box and backspace until it is empty. The hydrophobicity scale then defaults to last entered value, though the box remains empty.
2. Press Tab to move out of the hydrophobicity box. The hydrophobicity box remains empty, although the setting used in the tracks is the last value.
3. Note that when the box is empty, the slider bar reflects a value of 0.5, regardless of whatever the last value used. Thus you get a discrepancy between the slider bar value and the value reflected in the blobulated tracks.

Expected behavior: Once the user Tabs out of the entry box, if the box is empty, then it should fill in the default value being used and the slider bar should reflect this.

In this example below, I first set the hydrophobicity value to 0.3, and the tracks blobulate. Then I delete the hydrophobicity value in the entry box, and then tab out of it. This results in a state where the entry box is empty, slider bar reflects a value of 0.5, but the tracks are blobulated to a value of 0.3...