Preferences validation dialog is not given focus, so document is editable

[redmunds]

Recipe

1. Debug > Open Preferences File
2. Edit a defined preference to have an invalid value, such as:

"tabSize": { line: 0, ch: 0 },

1. Important: leave focus in editor
2. Ctrl+S (to save file) and F5 (to Reload Brackets)

Result
Modal Error Reading Preferences dialog is displayed, but focus is still in document and it's editable!

Expected
Dialog creates the illusion of modality. You can see this by clicking on dialog (without dismissing it) -- focus cannot be returned to document at this point.

[busykai]

@redmunds i'll take this one. added that dialog in the first place.

[redmunds]

Confirmed. Closing.