Merge pull request #1 from EpsilonX/song

merge
Create README.md
Merge pull request #2 from EpsilonX/song

fix segment fault
add method get_str to Store
add monitor to print out memory usage
start to write squash-server
in writing squash server
make the server listening
add client code, but not working now
start to write some scripts to crawl the top sites
fix server recv bug
update the script
add 500 top-sites of May 18
add a protocol for client and server
fix build error
able to put and get, but not together
make random testing working
Merge with Song