Implement Docker environments extraction

[Haehnchen]

Add support for enviroment of some common docker pattern. Please feedback before implementation there is a way i am doing it.

docker-compose.yml

web:
  environment:
    - DEBUG=1

docker-compose.yml

services:
  foobar:
    environment:
      - DEBUG=1

Dockerfile

ENV abc=hello
ENV abc=bye def=$abc
ENV ghi=$abc

[adelf]

@Haehnchen I see Docker and YAML plugins as a standard plugins for PhpStorm... so no problems here. I'm open for any advices :) . Thanks for good idea.

[Haehnchen]

its not about Docker and YAML is about the environment variables they provide. In additional to .env also extract values of given examples to provide support for them in getenv('DEBUG') and getenv('abc')

[adelf]

@Haehnchen I got it. I mean, these plugins already implemented languages for YAML and Dockerfile files, so it will be easy to use it.

[Haehnchen]

fyi: see DotEnvUtil.java https://github.com/Haehnchen/idea-php-symfony2-plugin/commit/d1853ff3c18b24a4acccf01685d1787460ce3d45

[adelf]

First draft pushed. Dockerfile support only. There are still a lot of work. I'm going to implement optional depending for Docker and YAML plugins. And also add needed extensionPoints.

[adelf]

In docker-compose.yml file can be two kind of env variables desclaration:

environment:
  RACK_ENV: development
  SHOW: 'true'
  SESSION_SECRET:

environment:
  - RACK_ENV=development
  - SHOW=true
  - SESSION_SECRET

Both of them implemented in 0.3 version. Currently it's in Jetbrains approval.