Add maven compiling configuration
Add activation property
Maven profiles aren't inherited, but properties are; by this way we are able to activate the plugin on all subprojects
Add Guava dependency
Introduce timeline beans
Add startTime to Goal bean
Add hashCode implementation to Duration
Correct toString method on MavenItem
Divide BuildEventsExtension to share utils methods
Timeline is only a container of projects
Only Goal has a duration aspect
Update Hamcrest version
Update Mockito version
Export a build as an HTML view named Timeline
Actualize README.md

Actualize README.md to explain the TIMELINE feature
Remove license from files
Logs are printed with DEBUG level
Add contributors to pom.xml
Remove body left border
Refactor the timeline contribution to match more closely with the style in maven-build-utils