Suggested changes to init
Suggested changes to init

- [SUGGEST] Added option '--overwrite' to overwrite changes to local
.impconfig
- [SUGGEST] Added option '--keepCode' to ensure that device/agent code
doesn't get overwritten with latest model code
- [SUGGEST] Added option '--keepDeviceCode' to ensure that device code
doesn't get overwritten with latest model code
- [SUGGEST] Added option '--keepAgentCode' to ensure that device code
doesn't get overwritten with latest model code
- [SUGGEST] After prompt "Create a new model" if model doesn't exist,
added code to actually create the model through the imp api.
- [SUGGEST] In case the local configuration already exists, and is being
overwritten, changes defaultDevice/AgentFileName is either the locally
saved name or the default name
- [BUGFIX] For Windows machines (or, at least my development machine),
cli-prompt has an issue (I've documented at
https://github.com/carlos8f/node-cli-prompt/issues/3) that makes chained
prompts behave improperly. Added workaround with prompt.multi()

deldrid1/imp-cli,matt-haines/imp-cli,cat-haines/imp-cli