[MANUAL MIRROR] Use portable Python for map merge hooks, other tools / Add .dmm merge driver (#2681)

* Use portable Python for map merge hooks, other tools (#55658)

* Add .dmm merge driver (#55699)

This is kind of a prototype. It only fully handles a few situations, 
and doesn't produce particularly easy-to-read conflict markers when it 
fails. I hope that it can be useful at least some of the time, can be 
improved over time, and that the lessons learned can influence a future 
interactive GUI conflict resolver (integrated into StrongDMM?). In the 
worst case, one can fall back to the tried and true "manually re-do one 
side's changes" strategy. 

**Automatic use**: In `tools/hooks/`, run `Install.bat`

**Manual use**, for Git GUIs that don't run merge drivers: while a 
merge is in progress, in `tools/mapmerge2/`, double-click `Resolve Map 
Conflicts.bat`

This PR also removes the error-prone "Prepare Maps.bat" / 
"mapmerge.bat" workflow. Those who aren't using the hooks should 
instead use `Run Before Committing.bat` before committing. First-time 
contributors who opened a PR without map merging can be advised to run 
`I Forgot To Map Merge.bat`.

* Fix loose double-quot in tradership_faction.dmm

Co-authored-by: Tad Hardesty <tad@platymuus.com>

tools/hooks/python.sh

@@ -1,32 +1,17 @@
 #!/bin/sh
-# `sh` must be used here instead of `bash` to support GitHub Desktop.
 set -e
-
-# Strip the "App Execution Aliases" from $PATH. Even if the user installed
-# Python using the Windows Store on purpose, these aliases always generate
-# "Permission denied" errors when sh.exe tries to invoke them.
-PATH=$(echo "$PATH" | tr ":" "\n" | grep -v "AppData/Local/Microsoft/WindowsApps" | tr "\n" ":")
-
-# Try to find a Python executable.
-if command -v python3 >/dev/null 2>&1; then
-	PY=python3
-elif command -v python >/dev/null 2>&1; then
-	PY=python
-elif command -v py >/dev/null 2>&1; then
-	PY="py -3"
+if [ "$*" = "-m precommit" ]; then
+	echo "Hooks are being updated..."
+	echo "Details: https://github.com/tgstation/tgstation/pull/55658"
+	if [ "$(uname -o)" = "Msys" ]; then
+		tools/hooks/Install.bat
+	else
+		tools/hooks/install.sh
+	fi
+	echo "---------------"
+	exec tools/hooks/pre-commit.hook
 else
-	echo "Please install Python from https://www.python.org/downloads/"
+	echo "tools/hooks/python.sh is replaced by tools/bootstrap/python"
+	echo "Details: https://github.com/tgstation/tgstation/pull/55658"
 	exit 1
 fi
-
-# Deduce the path separator and add the mapmerge package to the search path.
-PATHSEP=$($PY - <<'EOF'
-import sys, os
-if sys.version_info.major != 3 or sys.version_info.minor < 6:
-	sys.stderr.write("Python 3.6 or later is required, but you have:\n" + sys.version + "\n")
-	exit(1)
-print(os.pathsep)
-EOF
-)
-export PYTHONPATH=tools/mapmerge2/${PATHSEP}${PYTHONPATH}
-exec $PY "$@"