Initial Version
Interface unification work in progress
Squashed 'contrib/cmaketools/' content from commit 75cdaeb

git-subtree-dir: contrib/cmaketools
git-subtree-split: 75cdaeb9e99983e53e94c14cf0f7eaaf695bc284
Merge commit '9ca1cf8f9201bf328243b1ba540112b71a717df1' as 'contrib/cmaketools'
Fix entity build option.
Change warning to status.
Merge commit '75cdaeb9e99983e53e94c14cf0f7eaaf695bc284'

Conflicts:
	contrib/cmaketools/external_git.cmake
Merge commit 'd281fc3ae982d76d019a806b74bf9acab2583844' into unified_interface
Change warning to status
Merge commit '6180cb183532e497c9a67d00d0d0102f7cc46425' into unified_interface
Automatic configuration of external git projects.