Implement very rough "import" support.

Implement "import" recursing on a global level, not based on subdomains
and such.
Move import handling to data plugin.

Implement a new getValueProcessed call for the data plugin that
retrieves a name's value, decodes to a JSON object, and handles "import"
statements.  Use this in the DNS plugin instead of handling imports
there.
Merge pull request #6 from domob1812/import

"import" support in data plugin / new rpc call "getValueProcessed"