Mark upgrade steps whose profile's FS version is outdated.

Flags upgrades that lead to a destination version that is higher than the corresponding profile's current filesystem version. This usually means someone forgot to update the version in `metadata.xml` of the base profile.

![mark_outdated_fs_version](https://cloud.githubusercontent.com/assets/405124/3423693/919a083c-ffa5-11e3-8714-94315afe8c8a.png)

Currently only the *upgrade steps* that lead to a destination version higher than the profile's current FS version get flagged, not the profile itself, even though that's where the actual error lies. However, an upgrade step showing up in bright red should be enough for him to realize that he needs to check the corresponding profile's `metadata.xml`.

/cc @jone @maethu @phgross