static initialize Parser allowing for extension of parser

[willr3]

We should not change to a static instance. A shared Parser forces all Runs in the jvm to support any custom commands or yaml loaded into the Parser. This would limit the re-usability of qDup as a library. I didn't think the QDup class was part of the supported public interface for qDup. If we want to make it more re-usable then perhaps we make the Parser a private member variable with getters and setters?

[johnaohara]

The thought process for making it static was for reducing memory footprint. Seeing as no state is maintained in Parser wrt the document being parsed, the parsing definitions could be shared between Runs. Tbf idk if Yaml maintains state, so probably safer to have a new instance of Parser for each run

Is there a supported API for qDup defined anywhere?