Don't allow --style and --template for hg update and hg merge.
The only way that changesets will be shown with these command is in an error
message when trying to update to an ambiguous branch name.
abort: repository a not found!
255
requesting all changes
abort: error: Connection refused
255
abort: repository a not found!
255
abort: destination '../a' already exists
1
abort: repository a not found!
255
abort: destination 'q' already exists