[build] Move to python build scripts per module

This change moves Bonnibel from a separate project into the jsix tree,
and alters the project configuration to be jsix-specific. (I stopped
using bonnibel for any other projects, so it's far easier to make it a
custom generator for jsix.) The build system now also uses actual python
code in `*.module` files to configure modules instead of TOML files.
Target configs (boot, kernel-mode, user-mode) now moved to separate TOML
files under `configs/` and can inherit from one another.

scripts/bonnibel/version.py

@@ -0,0 +1,41 @@
+from collections import namedtuple as _namedtuple
+
+version = _namedtuple('version', [
+    'major',
+    'minor',
+    'patch',
+    'sha',
+    'dirty',
+    ])
+
+
+def _run_git(root, *args):
+    from subprocess import run
+
+    git = run(['git', '-C', root] + list(args),
+            check=True, capture_output=True)
+    return git.stdout.decode('utf-8').strip()
+
+
+def git_version(root):
+    full_version = _run_git(root, 'describe', '--dirty')
+    full_sha = _run_git(root, 'rev-parse', 'HEAD')
+
+    dirty = False
+    parts1 = full_version.split('-')
+    if parts1[-1] == "dirty":
+        dirty = True
+        parts1 = parts1[:-1]
+
+    if parts1[0][0] == 'v':
+        parts1[0] = parts1[0][1:]
+
+    parts2 = parts1[0].split('.')
+
+    return version(
+        parts2[0],
+        parts2[1],
+        parts2[2],
+        full_sha[:7],
+        dirty)
+