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- Rename the parameter ``dst_path`` to ``dest_path`` on ``install_plugin`` method.
- ``install_plugin`` now returns the name of the plugin when the installation is successful.
- Now the library path dir is added to ``PATH`` environment variable before load the library (Only on Windows).
- Added an optional "extras" entry to plugin definition yaml:
- "extras" is a dictionary for adding (key, value) customized options, accessible in ``PluginInfo.extras``;
- Plugin generation accepts a dict of default (key, value) pairs to be added to ``extras``;