This allows us to extend these and expose helpers for templates and
plugins.

This alows to add/remove flags instead of setting them.

Only inline forwarding is supported for now.

References: https://todo.sr.ht/~sircmpwn/koushin/37

This reverts commit 02faf6174b.

This commit doesn't work, because it's applied to <img> tags. Making it
handle <a> tags doesn't work either because bluemonday will strip any
target="_blank" attributes, making the compose form open in the
<iframe>. Let's just revert this whole commit for now.

Add a settings page where the user can change the number of messages
displayed per page.

References: https://todo.sr.ht/~sircmpwn/koushin/16

Note that attachments will be lost. This is a TODO.

And mark original message as answered.

Closes: https://todo.sr.ht/~sircmpwn/koushin/15

Take a *Context instead of a echo.Context. This saves a type assertion
in each handler.

This allows Go plugins to easily inject global data.

RenderData will be used for an interface.

References: https://todo.sr.ht/~sircmpwn/koushin/36

Maybe we should add a confirmation step in the future.

References: https://todo.sr.ht/~sircmpwn/koushin/36

References: https://todo.sr.ht/~sircmpwn/koushin/36

This is a public type other plugins and templates may want to access.

Closes: https://todo.sr.ht/~sircmpwn/koushin/13

Closes: https://todo.sr.ht/~sircmpwn/koushin/23

This gives more flexibility in Session for optimizations, e.g. keep the
SMTP connection around for some time if possible.

This plugin offers base IMAP/SMTP functionality.

References: https://todo.sr.ht/~sircmpwn/koushin/39

And unexport a few internal functions.

I'm uneasy exposing the token to plugins, I prefer to hide it if
possible to prevent mis-use.

This change allows plugins to logout users.

This allows plugins to access it.

GlobalRenderData contains some global metadata that can be obtained from
any template.

RenderData is a base type for template data. It contains a Global field
with global metadata and an Extra field for plugins.