composer/composer — pull request #667 by naderman (2012-05-09 13:58:17+00:00)
Title: Remove packages by default & handle aliases in solver

This moves all handling of deciding which packages to install into the solver. The solver will never request an alias to be installed but will always generate an install operation for the actual package. It will however generate MarkAliasInstalled and MarkAliasUninstalled operations, that allow the locker to keep track of aliases in repositories correctly.

Dumped repositories never contain aliases, but they can be reconstructed from branch alias info on the packages.