Remove project_apply

Networking operations on nodes now happen instantly.  The 'dirty' flag does
not exist.
Fix documentation and CLI for project_apply
http: Add missing json import.

This is used in the exception handler for APIError.
cli: Print help to stdout, not stderr.
Clean up testsuite a little

- Remove some redundant or useless tests
- Rename 'simple_vlan' tests for clarity
Remove references to 'apply' from comments and docs
Merge pull request #273 from zenhack/cli-help

cli: Print help to stdout, not stderr.
Merge pull request #274 from zenhack/missing-json-import

http: Add missing json import.
Remove unneeded deployment test

This test is covered by the null-vlan unit test.
Merge pull request #272 from gsilvis/transition

Remove project_apply