Simplify UAVOBrowser data range checking.

According to https://bugreports.qt-project.org/browse/QTBUG-13668, updating ranges of data currently is not supported. Removing this code simplifies the UAVO Browser and solves https://github.com/TauLabs/TauLabs/issues/745 and (potentially) https://github.com/TauLabs/TauLabs/issues/769.

#745 was due to the category view creating a different top-level tree, which meant that the browser wasn't properly detecting the change state. By removing these checks (since they were useless anyway), anytime the UAVO updates the browser will update either 1) when the timer expires or 2) immediately if an ON_CHANGE UAVO is expanded.