move clean action to it's own cookbook

removed clean from dependencies default recipe
created clean-specific cookbook
remove check for /etc/.provisioned file
remove cpu execution cap vbox setting
remove setup_mongodb step from install recipe
move mysql install recipe steps into default
moved local recipe variables out into attributes
uncomment commented out cookbooks in vagrantfile
move mongodb install steps into default, remove install recipe
remove next step notifications
remove duplicate install of scons
add zsh to package dependencies, remove from oh my zsh default recipe
Create README.md
Update README.md
fix zshrc and rvmrc echos
fix oh my zsh install recipe
add prerequisites, customization, and known issues sections to the readme
add private network setting to the vagrantfile
add instructions on skipping provisioning to the readme
add source command to /etc/profile to install_rvm recipe
add to do section to the readme