terminal-window: Factor CSDs into geometry hints
It seems Wayland-based window managers provide additional decorations
that we're not tracking in our "preferred size" computations. This means
every geometry update shrinks the window by a bit.
Factor in the allocated dimensions, not just the preferred ones.
Borrows some ideas from
https://bugzilla.gnome.org/show_bug.cgi?id=769898
I also drop a few unused values leftover from gnome-terminal.
Fixes #350
Avoid unprocessed file URIs being pasted to the terminal.
The `uris_as_paths` member, which is set to `true` when the paste
command has been triggered by the **Paste Filenames** action, was being
checked too late: a file URI was ultimately being entered to the
terminal, as opposed to the expected plain text version.
Test plan:
- Copy a file in Caja, or in any other file explorer that inserts the
`text/uri-list` and `text/plain` MIME formats into the clipboard.
- Paste the file in a MATE Terminal either via `Ctrl+Shift+V`, or via
the **Paste** action in the context menu.
Without this change, a file URI is entered. For example:
```
file:///home/jane.doe/my%20pictures/foo%20bar.jpg
```
With this change, a regular filepath [that the filesystem can recognize]
is pasted. For example:
```
/home/jane.doe/my pictures/foo bar.jpg
```
Note that the behavior of the **Paste Filenames** context menu action
remains unchanged (i.e. file URIs are still converted to regular paths
surrounded by single quotes).