Yang-maven-plugin refactored + fixed bugs.

Yang-maven-plugin refactored + fixed bugs.
Removed resourceProviders argument(unused).
Other arguments marked as optional.
Added argument to set whether use yang files from dependencies or not.
Added packaging of yang files from project to META-INF.
Added additionalConfiguration argument for code generators.

Yang-maven-plugin SPI, ResourceProvider interface removed since
it was unused. Code generator interface improved.

YangParserImpl API changed to provide a map<File, Module>. Users will
know which module belongs to which file and can utilize this information
when parsing yang files from multiple sources. Yang-maven-plugin needs
this information since it parses yang files from project as well as its
dependencies.

Change-Id: I15c53df59c4104793e023ad3686b031ce0ba8cd3
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>