Update options for composer schema file

[Guite]

The following items should be removed from the schema (for 2.0):

• package type zikula-plugin
• autoload psr-0

Also several items are missing (also for 1.4).

[Guite]

An updated schema file can be found here: https://github.com/zikula/core/pull/3151/files#diff-00c960787e161619463f9a2c9aef9962