Refactoring config, save functionality, display

Removing custom nepho_config in favor of built-in Cement IConfig, but
implementing save functionality for config file. Simplifying config,
removing unneeded values and putting scope in its own section. Cleaning
up/unifying display of cloudlet/blueprint and a bit of DRY in those CLI
components.  Plumbing in config changes and breaking out param
functionality.  Setting up proper param inheritance. Allowing providers
to specify and use params with lazy-loading and other trickery.
Disabling stack list test. Also this pull request fixes #149!
Improved template validation/display, fixed some issues with prompting
for provider credentials and other provider parameters.
Fixed broken show-template test
Merge branch 'master' into feature/149-refactor-configs

Conflicts:
	tests/stack_test.py
Merge pull request #179 from huit/feature/149-refactor-configs

Refactoring config, save functionality, display