Added cli.py for use with pyinstaller

cli.py

@@ -0,0 +1,19 @@
+""" stand alone command line script for use with pyinstaller
+    
+    To build this into an executable:
+    - install pyinstaller:
+        python3 -m pip install pyinstaller
+    - then use build_cli_exe.sh to run pyinstaller or execute the following command:
+        pyinstaller --onefile --hidden-import="pkg_resources.py2_warn" --name osxphotos --add-data osxphotos/templates/xmp_sidecar.mako:osxphotos/templates cli.py
+
+    Resulting executable will be in "dist/osxphotos"
+
+    Note: This is *not* the cli that "python3 -m pip install osxphotos" or "python setup.py install" would install;
+    it's merely a wrapper around __main__.py to allow pyinstaller to work
+    
+"""
+
+from osxphotos.__main__ import cli
+
+if __name__ == "__main__":
+    cli()