add profiling build script

Usage:
cd build
../etc/build.sh
./picrin file
gprof picirn gmon.out | less

etc/build.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/bash
+project_root=$(dirname $(pwd))
+for f in ${project_root}/src/*.c ${project_root}/extlib/benz/*.c ${project_root}/contrib/**/*.c ;do
+    gcc -c -O2 -pg -std=c99  -I${project_root}/extlib/benz/include $f -o `basename $f`.o &
+done
+wait
+gcc  *.o -O2 -I${project_root}/src -I${project_root}/extlib/benz/include -std=c99 -pg -lm -lreadline -o picrin
+rm *.o