Clean up comment
Clean up docstrings

Clean up docstrings for elwiki/commit-log and elwiki/http-commit-log.
Add missing `require'.

elwiki-vc-test.el was missing a (require 'elwiki-vc).
Expand docstring

Expand docstring for ERT test `elwiki/log->alist'.
Add test

Add test for `elwiki/log-alist->esxml'.