Adds support for contacts (Cards) marked as `external_resource` which
prevents modifications from happening. No way to import external
contacts is added yet.
CardId is the "Primary Key" of the contact type, Card. Meli-created
contacts had UUIDs for their CardId. In order to import external
contacts and ensure their primary key is the same each time, CardId is
made into an enum to add hashing as a choice.
- move set_seen to Listing component (instead of having it in Listing's
child Component)
- add default values to shortcut definition macro `shortcut_key_values`
- do not redefine default values in each `shortcuts` method after
getting all valid shortcuts from `context.settings.shortcuts.*.key_values()`
Page movements is an enum that describes the movements of the keyboard
keys "Home, End, PageUp, PageDown". Some mail listing Components
interpret these keys as changes to their cursors.
Use xterm window title escape sequences to set window title when
launched and restoring the previous one when exiting. If option is
blank, no title setting occurs.
If a listing lists search results, ie when "filtering" with a filter
term, it sets up its state in filtered_selection, filtered_order etc.
set_coordinates() should reset that state.
Attachment needs to know the range of bytes where the body part of the
attachment is located. The Attachment.raw field contains the entire
attachment, headers and body. The new Attachment.body fields contains a
`StrBuilder` which contains the offset and length of the body part inside
`raw`.
If Sent folder wasn't correctly configured, the sent message would be
lost. With this change it tries these folders in this order:
1. Sent
2. Inbox
3. Any other normal folder
The check is done by looking at the special usage metadata on each
folder. If everything fails, the message is saved in a file in the
tmpfs.
Check for pending events in the main process by receiving a timer event
every 300ms. This way loaded folders or received emails will get
recognized even if the appropriate informing signals got lost.
