Check units are already suggested before suggesting them.

This patch adds a missing check for already suggested units.
This check causes units not to be repeated in same physical interface, even when the interface has no vlan.

This patch additionally creates following methods for not repeating code:
- markAsSuggestedUnit
- markAsSuggestedVlan
And calls them where required.
Merge branch 'develop' of git://github.com/dana-i2cat/opennaas into fix/units-suggestion-repeats-values
Create VCPEVRRPCapability and store vrrp methods there.

This patch creates a new capability and moves already existing vrrp methods in VCPEBuilderCapability to it.
Create VCPEIPCapability and store updateIP method there.

This patch creates a new capability and moves already existing ip methods in VCPEBuilderCapability to it.
Merge pull request #494 from isartcanyameres/fix/units-suggestion-repeats-values

Fix/units suggestion repeats values
Merge pull request #495 from isartcanyameres/feature/move-capabilities-out-of-builder

Feature/move capabilities out of builder
Merge pull request #496 from jordi-puig/develop

Create fake template to test
Merge branch 'develop' of git://github.com/dana-i2cat/opennaas into develop
Error in redirection updateIps