Add support for war packaging, and missing documentation for options.

This pull request:
* adds missing documentation for most if not all undocumented options
* resolves the mismatch between options.type and options.packaging. options.type is effectively an override value for options.packaging.
* adds support for war packaging

From my reading of the code, it appears that the options.type parameter was introduced as a workaround for the options.packaging parameter being used to determine the compression mode used by grunt-contrib-compress.

My changes disconnect the packaging parameter from the compression mode so we can set packaging more freely. During the maven_deploy:package task, the code now uses the packaging to look up the compression mode by packaging, instead of using the packaging as is.

The initial table uses 'zip' mode for both 'jar' and 'war' packaging.

I also changed the semantics of the 'options.type' parameter so it is simply an override of the 'options.packaging' parameter. If both are present, 'options.type' wins. As they are now redundant, I marked the 'type' parameter as deprecated in the README.

Using the packaging parameter directly also allowed for the removal of the file renaming function, as the correct file extension is now used from the start.