Making phpBB Composer Ready

[MichaelC]

In order to keep BC for extensions with phpBB, allow phpBB to be installed using a composer command (see below) and allow phpBB to use composer to install extensions a few small changes are required:

• Adding metadata to the main composer.json to make phpbb into a composer package (olympus)
• Adding phpBB to packagist
• Changing the type in extension's composer.json from phpbb3-extension to phpbb-extension
• Require https://github.com/composer/installers in our composer.json
• Extensions require a version of phpbb/phpbb managed through packagist

Create project command example usage (note, it would download the repo as is, not the built package):
Download phpBB for olympus development: composer create-project phpbb/phpbb olympus-dev/ --keep-vcs --dev 3.0.* -s dev
Download latest stable olympus not for development: composer create-project phpbb/phpbb olympus/ 3.0.*
Download phpBB develop branch: composer create-project phpbb/phpbb develop/ --keep-vcs --dev dev-master -s dev
Download 3.0.12: composer create-project phpbb/phpbb 3.0.12/ 3.0.12

This doesn't break BC except with already created extensions (type & phpbb requirement changes).

[Jacob]

BC = backward compatibility.

[MichaelC]

Just a clarification, this isn't wouldn't become the way of installing phpBB for end users, just for developers as it installs deps and downloads the repo all at once in an easy command.