Format c++ files using clang-format

Add git pre-commit hooks to help with automatic formatting.

misc/hooks/canonicalize_filename.sh

@@ -0,0 +1,48 @@
+#!/bin/sh
+
+# Provide the canonicalize filename (physical filename with out any symlinks)
+# like the GNU version readlink with the -f option regardless of the version of
+# readlink (GNU or BSD).
+
+# This file is part of a set of unofficial pre-commit hooks available
+# at github.
+# Link:    https://github.com/githubbrowser/Pre-commit-hooks
+# Contact: David Martin, david.martin.mailbox@googlemail.com
+
+###########################################################
+# There should be no need to change anything below this line.
+
+# Canonicalize by recursively following every symlink in every component of the
+# specified filename.  This should reproduce the results of the GNU version of
+# readlink with the -f option.
+#
+# Reference: http://stackoverflow.com/questions/1055671/how-can-i-get-the-behavior-of-gnus-readlink-f-on-a-mac
+canonicalize_filename () {
+    local target_file="$1"
+    local physical_directory=""
+    local result=""
+
+    # Need to restore the working directory after work.
+    local working_dir="`pwd`"
+
+    cd -- "$(dirname -- "$target_file")"
+    target_file="$(basename -- "$target_file")"
+
+    # Iterate down a (possible) chain of symlinks
+    while [ -L "$target_file" ]
+    do
+        target_file="$(readlink -- "$target_file")"
+        cd -- "$(dirname -- "$target_file")"
+        target_file="$(basename -- "$target_file")"
+    done
+
+    # Compute the canonicalized name by finding the physical path
+    # for the directory we're in and appending the target file.
+    physical_directory="`pwd -P`"
+    result="$physical_directory/$target_file"
+
+    # restore the working directory after work.
+    cd -- "$working_dir"
+
+    echo "$result"
+}