Investigate if SnakeYAML might expose "anchor-resolved" model to use

[cowtowncoder]

(note: follow up to #98)

Since SnakeYAML provides information on anchors, references, and since it can natively resolve these in some modes, it might be worth looking to see if such input could be used instead of current event stream approach. If so, we might want to either convert existing parser to use that mode, or, if there is significant additional overhead, offer a feature to do so.

Note that this is sort of alternative to #120.

[cowtowncoder]

Note: one obvious concern is that of handling cycles. Not sure how those could actually be exposed, considering that streaming API should not produce infinite stream...