Zig build v0.16 compatibility

[precla]

Includes commits from #4

mbedtls path currently points to my fork, since that is also adapted for zig 0.16.0

needs this to be merged into actonlang/mbedtls : actonlang/mbedtls#1

[plajjan]

mbedtls is part of acton base, so if we need to upgrade to 0.16 we need to upgrade all of acton to use zig 0.16 - I am working on that, plxz stay tuned :)

[plajjan]

actonlang/acton#2807 - it is done. More importantly though, I would like to draw attention to how I switched over to a new structure for including C libraries and bindings for them.

The last commit on https://github.com/actonlang/acton-zlib changes so the build.zig for the C library zlib now points to deps/zlib/build.zig - so that is where we keep the build.zig for the zlib C library itself - the actual C source code for zlib is then in turned pulled down by zig from the upstream zlib git repo. We no longer need our own git repo mirror of zlib (used to be https://github.com/actonlang/zlib but is now removed). I believe we can do the same thing here, i.e. ditch having our own fork of libssh with patches + build.zig and instead just have a deps/libssh/build.zig in the acton-ssh repo

[precla]

actonlang/acton#2807 - it is done. More importantly though, I would like to draw attention to how I switched over to a new structure for including C libraries and bindings for them.

The last commit on https://github.com/actonlang/acton-zlib changes so the build.zig for the C library zlib now points to deps/zlib/build.zig - so that is where we keep the build.zig for the zlib C library itself - the actual C source code for zlib is then in turned pulled down by zig from the upstream zlib git repo. We no longer need our own git repo mirror of zlib (used to be https://github.com/actonlang/zlib but is now removed). I believe we can do the same thing here, i.e. ditch having our own fork of libssh with patches + build.zig and instead just have a deps/libssh/build.zig in the acton-ssh repo

done, see acton-ssh#PR4