This will overwrite an existing dependency if it is found. In other words, if a dependency on PHP 4.1.0 exists, and addDependency('php', '4.3.0', 'ge', 'php') is called, the existing dependency on PHP 4.1.0 will be overwritten with the new one on PHP 4.3.0
Dependency element name
Dependency version
A specific operator for the version, this can be one of: 'has', 'not', 'lt', 'le', 'eq', 'ne', 'ge', or 'gt'
Dependency type. This can be one of: 'pkg', 'ext', 'php', 'prog', 'os', 'sapi', or 'zend'
TRUE if dependency is optional