Declare family.versionnumber and site.versionnumber as deprecated

There is a more precise method to compare versions by using
LooseVersion from distutils.version whereas versionnumber() for
"2.1wmf3" looks very strange with 1001. With LV we can also compare
the build number.

remove versionnumber() from old site method list

Change-Id: I442523c5b14ccf1a240e74e782c6b3f6f3139a0d
Merge "Declare family.versionnumber and site.versionnumber as deprecated"