Properly escape Drush args to handle spaces in file paths
Update README.md
Cache the list of environments.
Make drush-aliases use the cached environments properly.
Improve checkout command usability.
Improve choosing environments in get command.
Mark the current environment in the checkout options.
List environments if 'platform branch' is called with no arguments.
String consistency
Hide URLS by default in environments list (so it's not too wide).
Add confirm steps for commands.
Add --yes and --no options, replacing --no-interaction.

Replace 'dialog' with 'question' throughout.
fopen() not file_open()
Fix undefined $environmentList
Merge branch 'master' of github.com:platformsh/platformsh-cli

Conflicts:
	src/Toolstack/DrupalApp.php
Merge branch 'envs-hide-urls-by-default' of git://github.com/pjcdawkins/platformsh-cli into envs-hide-urls-by-default
Support Sf2-style option specs. Resolves #143 yay.
Merge pull request #123 from pjcdawkins/yes-no

Add --yes and --no options, replacing --no-interaction.
Merge pull request #134 from pjcdawkins/update-readme

Update README.md
Update README.md