Pass configuration to Filesystem::__construct() even if an adapter is given as first argument.
Add config option to disable stream support.
Fix FilesystemConfig::has() return false on "false" or "null" values.
Fix issue with undefined variable $value in FilesystemConfig::merge().
Add support to revert changes on a FilesystemConfig.
Correct the RootAdapter::getConfig() pass to Filesystem::getConfig().
Add FilesystemConfig tests.