add script to pre commit hooks for checking file permissions (#2322)

script/remove_exec_bit.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+for file in $(git diff --cached --name-only --diff-filter=ACM | grep -E '\.(cpp|hpp|txt|inc)$'); do
+    if [ -x "$file" ]; then
+        chmod -x "$file"
+        echo "[remove-exec-bit] Removed executable bit from $file" >&2
+    fi
+done