Use optional_commands for Puppet 2.6 compatibility

Without this, using the module with puppet 2.6 results in the
error: "Could not find a default provider for vs_bridge"

Fix suggested by Dan Bode via email
Make sure that created bridges are brought up
Added keep_ip flag for provider to move physical_interface IP to the bridge port
restored initial ovs (before fork) and added ovs_redhat instead
added timer
handling dhcp cases
fixed bridge mac address capture to make it resilient
fixed provider parameter
commented out mac address resiliency
adjusted default values
fixed vs_bridge provider for ovs_redhat
sleep_time is Fixnum
changed sleep parameter
fixe wrong bridge param
issue with File/String conversion
removed bracket
using keep_ip as a puppet::Boolean
Not using Puppet Boolean for now
remove extra end
puppet nightmare!
reversed to normal file manipulation
remove File.Open blocks
fixed wrong file name argument for search method