Implementation-Build attribute is missing from the manifest files

The MANIFEST.MF manifest in the Hippo jars used to have a Implementation-Build property that contains the build version.
This attribute is added by the buildnumber-maven-plugin.

The attribute is used in the CMS and Repository code to enrich error reports and system-properties administration page.

We should either re-enable the build version in the Manifest, remove the Implementation-Build code or find another way to provide this information (for example checking the jar file version).

hippo-cms-api-2.22.22 MANIFEST.MF :
Manifest-Version: 1.0
Archiver-Version: Plexus Archiver
Created-By: Apache Maven
Built-By: hudson
Build-Jdk: 1.6.0_45
Specification-Title: CMS API
Specification-Version: 2.22.22-SNAPSHOT
Specification-Vendor: Hippo
Implementation-Title: CMS API
Implementation-Vendor-Id: org.onehippo.cms7
Implementation-Vendor: Hippo
Implementation-Build: 44937
Implementation-Version: 2.22.22-SNAPSHOT