DOUBLE, INT, etc are reserved keywords on Windows. DataBrowser,
which is an application using SMTK as a library would fail to build on
Windows due to this issue. This MR appends an `Type` to them and
rewrites them in camel case.

This's CMB side MR. SMTK MR's SHA is
662b0cfbacfe82b244bbc84509907baf444f80a5.