Html and text files are not fixed to be UTF-8. The encoding is now
detected, which may not work for all files. Default/fallback will be
utf-8.
There is still a problem with mails that contain html parts not in
utf8 encoding. The mail text is always returned as a string and the
original encoding is lost. Then the html is stored using utf-8 bytes,
but wkhtmltopdf reads it using latin1. It seems that the `--encoding`
setting doesn't override encoding provided by the document.
The viewerjs library has some limitations. Sometimes PDFs are quite
blurry and some content is displayed scrambled. Switching to the
browsers build-in PDF viewer (for chromium and firefox) fixes this. So
while on mobile the viewerjs is the only working viewer, for desktop
use it might be desireable to use the browsers builtin viewer instead.
Each attachment is now first extracted into potentially multiple ones,
if it is recognized as an archive. This is the first step in
processing. The original archive file is also stored and the resulting
attachments are associated to their original archive.
First support is implemented for zip files.
Periodic tasks are special in that they are usually kept around and
started based on a schedule. A new component checks periodic tasks and
submits them in the queue once they are due.
In order to avoid duplicate periodic jobs, the tracker of a job is
used to store the periodic job id. Each time a periodic task is due,
it is first checked if there is a job running (or queued) for this
task.
This client can be used within the backend app and later in other
modules. The `OJoex` object is replaced with a better implementation
where the http client is initialized once on app start.
