Add support for transparently compressing ontologies using NanoHTTP

[gaurav]

We ran into some speed issues in January when temporarily hosting JPhyloRef on my personal VPN, and consequently had to compress the JSON file during transmission (PR phyloref/klados#179) and then uncompress it in JPhyloRef (PR #63). This is something that should be handled transparently by the browser (phyloref/klados#182) and by NanoHTTP, probably through changing a setting like in NanoHttpd/nanohttpd#177 (comment).

This issue tracks making changes to JPhyloRef to support phyloref/klados#182. We should also check whether the reduction in time is fully explained by the reduction in file size, and whether there might be other issues slowing down the transmission of ontologies to JPhyloRef.