Add 'env' subcommand to docktie_cli

[casimpania]

Idea is that it will show the exported environment variables that starts with DOCKTIE or PROJECT

(docktie > cooltool) ~$ env|grep "^PROJECT\|^DOCKTIE"|sort

where:

• DOCKTIE - are for platform variables
• PROJECT - except for $PROJECT_ROOTDIR, these are mostly defined in respective conf/*_env file.

So, this would involve changes to init.sh as well to auto-detect all declared PROJECT_ (except for PROJECT_NAME).
This is useful for things like shortcuts to BACKEND and FRONTEND or PARSER directories when working from command line.

Parsing for env would be something like this:

(docktie > cooltool) ~$ grep -v "^#\|^$\|^PROJECT_" env.sample
DOCKER_CONTAINER_PREFIX=example
AUTOSTART_PROJECT=0
DOCKTIE_SERVICES_TO_START=""

[casimpania]

Oops, didn't notice that output of docktie_cli env and `env|grep "^DOCKTIE|^PROJECT" are different.
Add to that PROJECT_ROOTDIR in docktie_cli is that of docktie.

However, the environment variables as seen by "env" are what's important. Lowering priority to LOW