filtering files for code check seperately to enable fast use of git pre-commit hook to check code style

ask user to install pre-commit hook when code style is checked

Tools/files_to_check_code_style.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+set -eu
+
+PATTERN="-e ."
+
+if [ $# -gt 0 ]
+then
+    PATTERN="$1"
+fi
+
+exec find src \
+    -path src/examples/attitude_estimator_ekf -prune -o \
+    -path src/examples/ekf_att_pos_estimator -prune -o \
+    -path src/lib/DriverFramework -prune -o \
+    -path src/lib/ecl -prune -o \
+    -path src/lib/external_lgpl -prune -o \
+    -path src/lib/mathlib -prune -o \
+    -path src/lib/matrix -prune -o \
+    -path src/modules/attitude_estimator_ekf -prune -o \
+    -path src/modules/commander -prune -o \
+    -path src/modules/mavlink -prune -o \
+    -path src/modules/navigator -prune -o \
+    -path src/modules/sdlog2 -prune -o \
+    -path src/modules/systemlib/uthash -prune -o \
+    -path src/modules/uavcan -prune -o \
+    -path src/modules/uavcan/libuavcan -prune -o \
+    -type f \( -name "*.c" -o -name "*.h" -o -name "*.cpp" -o -name "*.hpp" \) | grep $PATTERN
+