Import backtrace-cpp and integrate it into our main executable

Upstream release
https://github.com/bombela/backward-cpp/archive/v1.3.tar.gz

external/backtrace-cpp/builds.sh

@@ -0,0 +1,77 @@
+#!/bin/bash
+
+COMPILERS_CXX98=`cat<<EOF
+gcc-4.4
+gcc-4.6
+gcc-4.7
+gcc-4.8
+clang
+EOF`
+
+COMPILERS_CXX11=`cat<<EOF
+gcc-4.7
+gcc-4.8
+clang
+EOF`
+
+
+function mkbuild() {
+	local compiler=$1
+	local lang=$2
+	local buildtype=$3
+	local builddir="$4"
+	export CC=$compiler
+	export CXX=`echo $compiler | sed -e 's/clang/clang++/' -e 's/gcc/g++/'`
+	export CXXFLAGS="-std=$lang"
+	echo "Creating $builddir"
+	mkdir $builddir 2>/dev/null
+	(
+		cd "$builddir"
+		cmake -DCMAKE_BUILD_TYPE=$buildtype ..
+	)
+}
+
+function build() {
+	local builddir=$1
+	shift
+	make -C "$builddir" $@
+}
+
+function dotest() {
+	local builddir=$1
+	shift
+	make -C "$builddir" test $@
+	return 0
+}
+
+function do_action() {
+	local lang=$1
+	local action=$2
+	shift 2
+
+	for compiler in $COMPILERS; do
+		local builddir="build_${lang}_${compiler}"
+
+		if [[ $action == "cmake" ]]; then
+			buildtype=$1
+			mkbuild $compiler $lang "$buildtype" "$builddir"
+			[[ $? != 0 ]] && exit
+		elif [[ $action == "make" ]]; then
+			build "$builddir" $@
+			[[ $? != 0 ]] && exit
+		elif [[ $action == "test" ]]; then
+			dotest "$builddir" $@
+			[[ $? != 0 ]] && exit
+		elif [[ $action == "clean" ]]; then
+			rm -r "$builddir"
+		else
+			echo "usage: $0 cmake [debug|release|relwithdbg]|make|test|clean"
+			exit 255
+		fi
+	done
+}
+
+COMPILERS=$COMPILERS_CXX98
+do_action c++98 $@
+COMPILERS=$COMPILERS_CXX11
+do_action c++11 $@