transform gitsuper mechanism to be per system user

The user can now opt-into this system by creating a git repo at
$HOME/.local/share/dxt/gitsuper

hooks/pre-commit.d/03-record-supermodule-commit.py

@@ -8,10 +8,13 @@ from pathlib import Path
 import subprocess
 from configparser import ConfigParser
 from functools import partial
+import logging
+
 
 get_output = partial(subprocess.check_output, universal_newlines=True)
 root = Path(get_output(['git', 'rev-parse', '--show-toplevel']).strip())
 supermod = Path(root, '..')
+supermod_name = supermod.resolve().parts[-1]
 modfile_fn = root / '.gitsuper'
 
 
@@ -23,6 +26,20 @@ def get_env(mod):
     return env
 
 
+def _save_config(super, mod, cf):
+    target_dir = Path(os.path.expandvars('$HOME')) / '.local' / 'share' / 'dxt' / 'gitsuper'
+    if not target_dir.is_dir():
+        logging.error('Not a directory {}, skipping gitsuper committing'.format(target_dir))
+        return
+    target = target_dir / mod
+    os.chdir(target_dir)
+    env = get_env(target_dir)
+    with open(target, 'wt') as out:
+        cf.write(out)
+    subprocess.check_output(['git', 'add', str(target)], env=env)
+    subprocess.check_output(['git', 'commit', '-m', '"Updated {} from {}"'.format(mod, super)], env=env)
+
+
 def for_module(cf, mod, section=None):
     mod = mod.resolve()
     os.chdir(mod)
@@ -38,6 +55,8 @@ def for_module(cf, mod, section=None):
     except subprocess.CalledProcessError:
         pass
     cf.set(section, 'commit', commit)
+    return cf
+
 
 cf = ConfigParser()
 for_module(cf, supermod, 'supermodule')
@@ -46,7 +65,5 @@ for s in [Path(s) for s in
               get_output(['git', 'submodule', '--quiet', 'foreach', 'pwd'],
                          env=get_env(supermod)).split()]:
     for_module(cf, s)
-cf.write(open(modfile_fn, 'wt'))
+_save_config(supermod_name, root.parts[-1], cf)
 
-os.chdir(root)
-subprocess.check_call(['git', 'add', str(modfile_fn)])