Bugfix for update_port: dealloc port.ip_addresses

* updated tests to check for deallocate as well
Implemented DRY for update_subnet, updated tests
Bugfix: deallocate_ip_address in-loop deletion

* Refactored deallocate_ip_address such that list traversal was separate
from deleting elements from the list.
* Updated tests.
Implemented DELETE and GET /mac_address_ranges/<uuid>

* Added exceptions.MacAddressRangeNotFound,
  exceptions.MacAddressRangeInUse
* Implemented tests for plugin.get_mac_address_range
* Implemented tests for plugin.delete_mac_address_range
Adds unoptimized providernets support

Adds support for the providernets API hooks as well as alternate configs
for NVP lswitches and switch spanning.
Merge pull request #93 from Cerberus98/pnetapi_merge

Adds unoptimized providernets support
Merge pull request #85 from asadoughi/put_subnet_2

Implemented DRY for update_subnet, updated tests
Merge pull request #86 from asadoughi/delete_port_ip_fix

Bugfix for update_port: dealloc port.ip_addresses
Merge pull request #88 from asadoughi/dealloc_ip_fix

Bugfix: deallocate_ip_address in-loop deletion
added wiki submodule
Merge pull request #95 from jkoelker/wiki

added wiki submodule
Merge pull request #84 from asadoughi/delete_mac_address_range

Implemented DELETE and GET /mac_address_ranges/<uuid>