Added tag 5.4.0 for changeset 19cb181bb4d8

Prepare version 5.4.0

main packer widget: preserve a little bit more the preferred user orientation

for example, on a small screen size, if the user specify HORIZONTAL,
when the screen is reduced, we preserve the horizontal orientation.

main widget: allow user to specify a maximalized pane on startup.

main packer widget: preserve focus and maximalization while changing split orientation

Mostly, when the user reduces the window size, `gh` changes
automatically the split orientation. In this case, `gh` should
preserve the focused pane and maximalization.

To do so, We build the columns/pile widgets once and apply
focus/maximalization to both everytime.

widget: allow users to maximize the focused pane

Just enlarge the focused pane.

Note: users can maximize the patch pane, and browse the tree with
      `alt+{up,down}`.

widget: allow users to specify the default orientation

Related to https://todo.sr.ht/~alainl/lairucrem/4

widget: coding-style, use constant symbols

widget: coding-style

widget: code simplification

Guessing orientation depends only on the screen size. The previous orientation is meaningless there.

widget: let user choose main window splitting orientation

Related to https://todo.sr.ht/~alainl/lairucrem/4

widget: refactorization

widget: recompute the main widget orientation only when the screen size changed

There is no need to compute it every time.

setup: fix version

Added tag 5.3.1 for changeset 0b723df0c41f

HG 6.0 compat

process: unbloat the error popup trace

And use the logger for details.

process: better handling of misc mercurial errors (e.g. "no username supplied")

Mercurial uses code 255 for various error situations.
Here we use the error message to dispatch.

process/kill: do not swallow errors from mercurial in `stop`

Because the subprocess module yields an OSError (-9) on a killed
process, we have to swallow that exception.

That's all because we regularly kill subprocesses when the user
changes focus in the ui (e.g. browsing commits).

debug: fix the traceback popup size

`format_tb` splits on frame blocks, and we want plain lines