Change Version formatting properties and functions to return Version objects (#4834)

* Change version.up_to() to return Version() object
* Add unit tests for Version.up_to()
* Fix packages that expected up_to() to return a string
* Ensure that up_to() preserves separator characters
* Use version indexing instead of up_to
* Make all Version formatting properties return Version objects
* Update docs
* Tests need to test string representation

var/spack/repos/builtin/packages/magics/package.py

@@ -109,7 +109,7 @@ def install(self, spec, prefix):
         if '+metview' in spec:
             if '+qt' in spec:
                 options.append('-DENABLE_METVIEW=ON')
-                if spec['qt'].version.up_to(1) == '5':
+                if spec['qt'].version[0] == 5:
                     options.append('-DENABLE_QT5=ON')
             else:
                 options.append('-DENABLE_METVIEW_NO_QT=ON')