Add turbovisor for turbo framework

For now, turbovisor detects file changes within given directory.  In the long
run, turbovisor aims to be a built-in load balancer for turbo framework, much
like pm2 for node.js
add rm turboviso in Makefile uninstall
delete old turbovisor file under root directory
use INSTALL_X instead of cp for turbovisor installation
use /usr/bin/env for shebang interpreter

This fixes permission denied error in some Linux environment
Merge pull request #1 from houqp/turbovisor

two minor fixes
Added Turbovisor which looks for file changes in directory and reloads application.
Return proper error message when setting SO_REUSEADDR fails
Merge pull request #102 from rajatgoel/master

Return proper error message when setting SO_REUSEADDR fails