Replaced application descriptor containing deployment properties with
the deployment info specified by the client, which is extended for the
plugin, and is now the only deployment model used throughout the entire
plugin. Changed how the deployment info is edited via a working copy
model. Various other fixes related to application deployment.
Implemented initial support for manifest files. Added snakeyaml as a
dependency for parsing and writing to manifest files. Removed duplicate
deployment info validation, and now it is only present in the core
application delegate. Added default values to deployment information and
requests for default deployment info are delegated to the application
delegate instead of hardcoded throughout the plugin.