Add new Version property to handle joined version numbers (#2062)

* Add new version property to handle joined version numbers

* Add unit test for new joined property

* Add documentation on version.up_to() and version.joined

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

@@ -34,9 +34,9 @@ class Cfitsio(Package):
 
     version('3.370', 'abebd2d02ba5b0503c633581e3bfa116')
 
-    def url_for_version(self, v):
+    def url_for_version(self, version):
         url = 'ftp://heasarc.gsfc.nasa.gov/software/fitsio/c/cfitsio{0}.tar.gz'
-        return url.format(str(v).replace('.', ''))
+        return url.format(version.joined)
 
     def install(self, spec, prefix):
         configure('--prefix=' + prefix)