We should support the following scenarios around log4j.xml when auto upgrading agents:

1) add/update/remove entries in log4j.xml where the customer has *not* made any updates from the previous release.
2) add/update/remove entries in log4j.xml where the customer *has* made updates from the previous release. But the two sets of updates (ours and the customers) *can* be merged
3) add/update/remove entries in log4j.xml where the customer *has* made updates from the previous release. But the two sets of updates (ours and the customers) *cannot* be merged. In which case our updates should probably be used and the customers old updated version should be left alongside the new version for manual merging (e.g. similar to how rpm handles config file conflicts)