Build improvement

[stokito]

I opened the project in CLion IDE and it automatically created build directory executed the autoreconf command:

cd ./build
autoreconf --install --force --verbose "${PROJECT_DIR:-..}" 2>&1; /bin/sh "${PROJECT_DIR:-..}/configure"

The command upgraded Makefile.in file and I committed the change in 254d873

Also I added the build folder and all generated files to .gitignore.

Debian has own patched version that you can see in https://salsa.debian.org/lhw-guest/network-manager-ssh
When you release a new version your changes are merged https://salsa.debian.org/lhw-guest/network-manager-ssh/-/commit/0c5c71d60abbf56ce8588dbb529ea38b9b66b990

So it would be nice to grab those changes into the upstream code to minimize burden of maintaining.
Some changes in debian folder are safe to copy what I did in the c414baf

The Debian package also has a patch that renames the appdata folder to metainfo. This is more standard
https://wiki.debian.org/AppStream/Guidelines

So I applied the patch too.

The debian folder needs for some changes too but that needs to be changed and tested separately:

The debian/sources/format should be changed to 3.0 (native) because this is an original package. The debian/patches must be removed too.

The debian/compat uses version 8 which is ancient and must be updated to at least 11.

The debian/rules is over-complicated: it clones sources (of itself) from git. Instead ideally it should be just:

#!/usr/bin/make -f

%:
	dh $@

And everything else will be made by the debuild itself.

@lhw you are a Debian maintainer so can you please send a PR to make the upstream to be debianized out of the box?