Update basic copyright info
Merge branch 'doc-updates' of https://github.com/dwimsey/libRocket

* 'doc-updates' of https://github.com/dwimsey/libRocket:
  Update basic copyright info
satisfy CSS2 specification for LEFT, RIGHT, TOP, BOTTOM
Cleans up properties referring to a data source when the DataSource object is destroyed, fixes #137
Merge branch 'hotfix/issue-137'