draft: Put inline image draft race to rest

The solution is simple: upload the image, create the draft automatically,
attach the image to the draft, return the draft_id to the client. That's it.
There's no more need to create the draft in advance now.
Remove unnecessary callback for config
i18n: Add concept of translatable content
i18n: Open custom data translations to a wider world
i18n: Make topics, SLAs, lists, list items translatable
i18n: Localize team and group names
i18n: Site pages are translatable
i18n: Implement system language management
Implement client l10n of new ticket forms
i18n: Default to system primary language
i18n: Make the translate widget show a flag

to indicate the primary language expected for translatable content
i18n: Make textarea inputs translatable
Add draft support for site page translataions
i18n: Access content templates are translatable
i18n: Save browser language on login

This will help if the user has "Browser Preference" selected as the
preferred language. When email correspondence needs to be sent to the user,
the browser_lang extra attribute can be used as a backup to to the user's
language preference in the event that the language preference is set to auto
(Browser Preference).
i18n: Send translated email correspondence
Fix incorrect HTTP cache detection
Add new translation table
i18n: Add missing CSS for translatable widget
i18n: Fixup several install related issues