Added vnics and security groups to the jargon page
Merge branch 'master' into jargon-update

Also updates the security group description

Conflicts:
	Jargon-Dictionary.md
Put some links in the security groups description
Added the jargon dictionary to the sidebar
Got rid of the pointless split between vnic and vif
Added backup object, added machine image, fixed faulty description of endpoint, fixed broken link in security groups.
Fixed links throughout the jargon dictionary
Fixed a heading that was accidentally deleted
Fixed link to the vnic header which was changed
Simplified link to security groups page
Added links to the word instance
Fixed grammar mistake in the Jargon dictionary
Improved vnic description
Merge pull request #3 from axsh/jargon-update

Added some terms to the jargon page