Moving gray bar in Working Tree when there are modified files.

[mgorra]

Normally there is a thin gray line in the Working Tree to separate the select all button from the files. However, when all the files present in the Tree are ConflictingThenModified, the bar moves down a line with every pass of the RepositoryMonitor, looping when it reaches the bottom.

[dmusican]

Changing this to high priority because I'm concerned about what this might mean under the hood. This might be a harmless bug, but it might not be.