Initialize status FIFO pointer
Prevent node transplantation for `circulate`
Add new contributor
Remove message: `ungrab_pointer`

The above message was only needed for ending the `move` pointer action
on a floating window. It rendered the `move` pointer action finicky
because the floating rectangle of the floating windows was not updated
in real time.
New setting: `auto_cancel`
Don't try to send/drop a NULL node
Refresh TODO list
Follow nodes transfered via `shift`
Indicate emphasis via the apostrophe character
Rewrite message handling

The new message syntax:
- Provides 10 commands instead of 60.
- Allows multiple actions to be applied in one call.

The client now returns an non zero exit code when a message fails.

The `is_adjacent` function now handles vacant nodes.
Prevent focus change due to pointer jitter
Use the standard `abs` function
Don't alter focus when transplanting nodes
Finish updating examples for the new syntax
Start writing miscellaneous documentation
Refocus the focused node in `transplant_node`
Remove `<file_path>` arguments from control flags.

Neither `--adopt-orphans` nor `--put-status` should have arguments.
Expand single-use definitions

Replace all single-use documentation constants with their actual values.
This makes the documentation easier to follow (less cross-referencing).
Expand selector documentation.

Instead of simply listing selectors, describe how they work explicitly.
Merge branch 'expand-selector-documentation'