Added classes.
SkillTree and Dao access.
Added missing constant and SkillTree component.
Revert "Added missing constant and SkillTree component."

This reverts commit 1b9b092a24615f4f4d5ea63131867d99cdeca4e5.
Added missing constant.
Added action buttons to form.
Added tree component.
assignedUser -> responsibleUser.
Merge branch 'master' of git.micromata.de:projectforge/projectforge-webapp