mixed PEAR_Dependency::checkExtension (
, string $name
, string $req
, string $relation = 'has'
Extension dependencies check method
this variable will contains an error message, if check fail
Name of the extension to test
Required extension version to compare with
How to compare versions with eachother
FALSE if dependency could be resolved
successfully(!); or an
in case of an unresolved dependency.
This function can not be called statically.