Added capability to specify explicit security group for each slave template
Moved security group preprocessing logic to a separate method
Updated JClouds to 1.7.1 (fixes bug related to VLAN selection in Openstack and many more) and other dependencies (Google Guava, Stapler, Jenkins Plugin) to recent versions
1) Fixed an issue with security group saving
2) Added capability to specify network UID (VLAN) for Openstack
Removed magic number from JCloudsSlaveTemplateTest
Added capability to specify networks requirements for any provider
Added capability to specify security groups requirements for any provider
Migrated csv parsing logic to opencsv library
Merge pull request #60 from vania-pooh/master

Added capability to specify security groups and networks requirements for any provider