Addressing review feedback:

* removed mail-app_test.js to mail_app_test.js but don't delete the original.
* remove search mail from HTML serialization
* .PHONY: all
* update_shared now just does a cp -rp, and there is a SHARED_JS_SOURCES that gathers all the shared resources. I had the old setup because just a plain cp -r did not seem to correctly trigger an update in either the copied shared directory or in the built file, I forget which. But it led to me just doing the rm every time since I did not trust that shared was up to date. Hopefully the cp -rp and the SHARED_JS_SOURCES will address that now, but I am still weak with Make-fu.
* typo for template path in apps/email/js/cards/settings_account_credentials.js
* shared/mime_mapper not included