Make create_configuration hookable to support multiple runtime configurations

[proboscis]

Currently we have either viz/run for the options to run Injected. viz -> show dependency graph on a browser run -> runs it locally.

However, there are cases where a user wants to customize how an Injected should be treated.

1. Make create_configurations return generic run configuration:
   • Currently, create_configurations returns a json of IdeaConfigurations
2. Make create_configurations look for hooking designs, or retrieve hooks from a design 2.1 Use a special name such as default_design_paths 2.2 look for a special dependency injection variable name such as runtime (this looks better)
3. Make the 'viz' feature a runtime option

[proboscis]

1. We can look for "__runconfig_...." variables in a design at default design paths.
2. We can look for a injected variable that creates configurations for idea
3. For each script file there must be overriding options as an entry point. This means that we should look for a design rather than a "default_design_paths" So let's introduce "__metadesign__":Design and deprecate "\_default_designpaths_\"

[proboscis]

The protocol for __metadesign_\: 'overriding' the parent by default. So, if you have a meta_design in a root of a module, it will be used, and it can be overridden in child modules by defining meta_design

[proboscis]

implemented __meta_design__ and added 'IdeaConfigCreator' type. now we can bind custom_idea_config_creator with type IdeaConfigCreator to be invoked by config creator.

[proboscis]

Implemented with branch #2