Improved usage function by using heredoc
Improved help message.
Added information output when trying to destroy a current vagrant instance.
Added common docroot names to be checked for existence if no shared folders are specified.
Added ability to add port forwardings.
Added default vagrant box
Converted variable SHARED_FOLDERS and FORWARD_PORTS to array
Added validation of shared folders. They also get written in ruby format to be directly added to Vagrantfile
Added validation of forwarded ports.
Added functionality to write configuration to Vagrantfile
Fixed port forwarding.
Added configuration of port forwarding to Vagrantfile