add profiling build script
Usage:
cd build
../etc/build.sh
./picrin file
gprof picirn gmon.out | less
Merge branch 'master' of github.com:picrin-scheme/picrin
WIP: Add (picrin socket) and (srfi 106).

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>