Some cleanup to handling TemplateRequest responses

 * Seems like we were caching errors

 * Also removes some dead code

Change-Id: Ie8f1d94069f38e31498969a06fc49c46cf08650b
Update page id|ns instead of setting them on meta

 * Having this data in two places led to the confusion in
   0ea76a6a69180bdf32aec008792bc8b061e18098.

 * Also renames env.reset to initializeForPageName and sets a default
   page name on the env prototype to avoid the duplicate places where
   it's hardcoded.

Change-Id: I031259819d219cbf569a04de5b5d818446880132
Merge "Some cleanup to handling TemplateRequest responses"
Merge "Update page id|ns instead of setting them on meta"