* functions: application updates no longer accept name in the body
AppUpdate was initially conceived as an upsert endpoint for apps.
It turns out that it created an inconsistency regarding updates:
updates with names divergent with URL would not actually change
application's name.
This commit atempts to address the issue by returning an HTTP
error when trying to update an application name. In swagger.yml,
application names are already `readOnly:true`. Thus there is no
change from expected behavior.
Fixes#380
* functions: use specific error value for name change
* More doc updates, explanation of serverless.
* Moved howto directory to examples and some minor doc updates.
* Added apps and routes docs.
* Fixes for Carlos' comments.
* Added bit about importing lambda functions.