Initialization processor doesn't handle deprecated extensionbuild property correctly

The hipposys:extensionbuild property was previously used to store the implementation build number in manifest that is used to determine whether a reloadable item needs to be reloaded. We now have two options: specify hippo:version property on item itself or use implementation build number in manifest for module-wide reloading. When a hippo:version property is provided it must not be compared to any previous implementation build number, but only to previous item-specific version number. This is not the case and must thus be fixed.

The hipposys:extensionbuild property was deprecated in favor of hippo:extensionversion property. In fact, the former must act as a fallback for the latter. This is not the casea and must also be fixed.