Split out grumphp configuration into magento2 and pimcore options

2.15.0

Added

• Project type resolver can now look for pimcore projects.
  • Pimcore projects have their own git blacklist configuration.
  • In the future, the pimcore coding standard will have its own package for phpcs.xml and phpmd.xml rulesets.
• grumphp.yml file for pimcore projects.
  • This file falls back on the default configuration and inherits all properties, except for the blacklist triggers.
• Git blacklist documentation.

Changed

• The magento2 grumphp.yml file is split off from the default configuration.
  • The grumphp.yml that's part of a project will automatically point to the new magento2-specific config file.
  • The new file falls back on the default configuration, and overrides the git blacklist keywords and triggers.
  • The magento specific constructs are also removed from the default grumphp.yml template.
• The default phpcs.xml file now references a relative ruleset instead of an absolute path.