added deep copy options

git-svn-id: http://ifcplusplus.googlecode.com/svn/trunk@28 315f8137-1bae-fbf7-f064-ab920df865c0
git-svn-id: http://ifcplusplus.googlecode.com/svn/trunk@29 315f8137-1bae-fbf7-f064-ab920df865c0
git-svn-id: http://ifcplusplus.googlecode.com/svn/trunk@30 315f8137-1bae-fbf7-f064-ab920df865c0
r30 Merge branch 'master' into readme