puzzles: tooling to automate the resyncing process

This adds a resync.sh script that handles most of the resyncing process:
copying new sources, regenerating help, and staging for commit. I also took
this opportunity to make the process more efficient and consistent by only
selecting the types of files that we care about and ignoring any
autogenerated temporary files that may be in the upstream tree.

Change-Id: Ib0803462684b8ae3b40eec3742944e5bdb28508e

apps/plugins/puzzles/genhelp.sh

@@ -1,10 +1,10 @@
 #!/bin/bash
 # usage: ./genhelp.sh
 #
-# expects halibut to be installed in $PATH:
-# http://www.chiark.greenend.org.uk/~sgtatham/halibut
+# Expects halibut to be installed in $PATH:
+# https://www.fwei.tk/git/halibut
 #
-# also requires host CC and lz4 library to be available
+# Also requires host CC and lz4 library to be available
 
 halibut --text src/puzzles.but
 

apps/plugins/puzzles/resync.sh

@@ -0,0 +1,44 @@
+#!/bin/sh
+# Usage: resync.sh PUZZLES_PATH
+#
+# Automatic resync tool. Removes the current source snapshot in src/
+# and copies just the source files we need from the puzzles source
+# tree. Handles help generation as well. Stages changes in git.
+#
+# Expects a modified Halibut (https://www.fwei.tk/git/halibut) to be
+# installed in $PATH. Also requires host CC and lz4 library to be
+# available
+
+
+if [ $# -ne 1 ]
+then
+    echo -e "Usage: $0 PUZZLES_PATH\n"
+    echo "Automatically resync with upstream."
+    echo "PUZZLES_PATH is the path to a puzzles source tree."
+    exit
+fi
+
+echo "=== POTENTIALLY DANGEROUS OPERATION ==="
+echo "Are you sure you want to remove all files in src/?"
+echo -n "If so, type \"yes\" in all caps: "
+read ans
+if [ "YES" == $ans ]
+then
+    pushd "$(dirname "$0")" > /dev/null
+
+    echo "[1/5] Removing current src/ directory"
+    rm -rf src
+    echo "[2/5] Copying new sources"
+    mkdir src
+    cp -r "$1"/{*.c,*.h,*.R,*.but,LICENCE,README} src
+    echo "[3/5] Regenerating help"
+    ./genhelp.sh
+
+    echo "[4/5] Staging for commit"
+    git add src help
+    echo "[5/5] Successfully resynced with upstream"
+
+    popd > /dev/null
+else
+    echo "Did nothing."
+fi