Adding and using get item from tier method.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@14857 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Removing set data model from original method.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@14858 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Using new method from seqmapview interface.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@14859 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Optimizing delete feature method.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@14860 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Adding unchecked warning

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@14861 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Cast to return type.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@14862 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Merge remote-tracking branch 'upstream'