Update README to note libvirt-dev requirement

The libxml-devel note was helpful, but I needed libvirt-devel too
Merge pull request #12 from supercow/libvirt-dev_doc_update

Update README to note libvirt-dev requirement
Tool for RedHat image preparation.
Fix for requiretty disabling in sudoers file.
Don't use DNS in /etc/ssh/sshd_config file setup.
Switch off iptables and SELinux to permissive mode.
IP of VM is searched in dnsmasq lease files only.
Provider options cpu and memory added. Those are used while creating
a new domain.
v0.0.3
Version changed to 0.0.3
fix run_provisioner
Merge pull request #17 from pronix/master

fix issue with run_provisioner
Exception handling while starting a domain.
add handleBoxUrl for download box close #15
Merge pull request #20 from pronix/master

close issue #15 for download box automaticaly
add actiob ssh_run for command `vagrant ssh -c "bash cli" ` close #13
Merge pull request #21 from pronix/master

close issue #13 for exec cli
v0.0.4
nested virtualization
Merge pull request #22 from pronix/master

nested virtualization (VMX)
* Private network support.
* Creating private networks if ip address is set and network
  is not available.
* Guest network interfaces configuration.