Simplified HistoryGraph by replacing Canvas of Shapes/TextBlocks with Listbox using DataTemplate of custom PlotCommitElements
Added style to HistoryGraphView to force selection background color to overcome potential issues with different Windows color schemes clashing with colors used to render PlotCommits
HistoryGraphView: Tweaked appearance of labels, also PlotCommitElements now share static renderer.
HistoryGraphView: Color coded the ref labels and added a legend at the bottom. Now have red heads, green-to-go tags, and remotes as deep as the sea. Kept CornflowerBlue for the remainder.
HistoryGraphView: Added Clear() and SelectedHash property. Set ListBox virtualizing mode to Recycling. BrowserView now uses new SelectedHash in SelectCommit() to ensure current commit gets highlighted.
HistoryGraphView: Added ref jump lists.
BrowserView: Fixed redundancy introduced in last commit
Catch possible exceptions when populating jump lists
Merge remote-tracking branch 'CyDragon80/master'