some fixes of entries, datatable html and git archive python code

tools/git_archive/README.txt

@@ -0,0 +1,5 @@
+Clones and/or pulls many git repositories from the open source games entries, so that one has an archive of them.
+
+Currently requires at least 35 GB space!
+
+Run update.py to update the archive. Git URLs are stored in archives.json.

tools/git_archive/update.py

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+"""
+    Clones and/or pulls all the gits listed in archives.csv
+
+    Requires: git executable in the path
+
+    Warning: This may take a long time on the first run and may need a lot of storage space!
+"""
+
+import os
+import json
+import subprocess
+
+
+def read_text(file):
+    """
+    Reads a whole text file (UTF-8 encoded).
+    """
+    with open(file, mode='r', encoding='utf-8') as f:
+        text = f.read()
+    return text
+
+
+def derive_folder_name(url):
+    github = 'https://github.com/'
+    if url.startswith(github):
+        parts = url[len(github):].split('/')
+        parts.insert(0, 'github')
+        folder = '.'.join(parts)
+    return folder
+
+
+def clone(url, folder):
+    result = subprocess.run(["git", "clone", url, folder])
+    if result.returncode:
+        print(result)
+
+
+def pull():
+    result = subprocess.run(["git", "pull", "--all"])
+    if result.returncode:
+        print(result)
+
+
+if __name__ == '__main__':
+
+    # get this folder
+    root_folder = os.path.realpath(os.path.dirname(__file__))
+
+    # read archives.json
+    text = read_text(os.path.join(root_folder, 'archives.json'))
+    archives = json.loads(text)
+
+    # loop over archives
+    for archive in archives:
+        folder = os.path.join(root_folder, derive_folder_name(archive))
+
+        # if not existing do the initial checkout
+        if not os.path.isdir(folder):
+            os.chdir(root_folder)
+            clone(archive, folder)
+
+        # pull all
+        os.chdir(folder)
+        pull()
+
+
+
+