* adds more intelligent save logic and diff to network config modules
* adds sha1 property to NetworkConfig
* adds new argument save_when to argument_spec
* adds new argument diff_against to argument_spec
* adds new argument intended_config to argument_spec
* renames config argument to running_config with alias to config
* deprecates the use of the save argument
* before and after now work with src argument
* misc module clean
Modules updated
* nxos_config
* ios_config
* eos_config
Most notably this makes the save mechanism more intelligent for config
modules for devices that need to copy the ephemeral config to
non-volatile storage.
The diff_against argument allows the playbook task to control what the
device's running-config is diff'ed against. By default it will return
the diff of the startup-config.
* removes ios_config from pep8/legacy_files.txt
* extends the ignore lines argument to the module
* clean up CI errors
* add missing list brackets
* fixes typo
* fixes unit test cases
* remove last line break when returning config contents
* encode config string to bytes before hashing
* fix typo
* addresses feedback in PR
* update unit test cases