[ENSCORESW-737]. Faster gene tree serialisation.
[ENSCORESW-737]. Faster gene tree serialisation.

We now use the preload() function on a GeneTree to fetch lots of info
from the server. Local tests suggest it wins back half a second or so. If anything
it is fewer trips to the server

willmclaren/ensembl-rest,willmclaren/ensembl-rest,ens-lgil/ensembl-rest,ens-lgil/ensembl-rest,helensch/ensembl-rest,helensch/ensembl-rest,willmclaren/ensembl-rest,ens-lgil/ensembl-rest,ens-lgil/ensembl-rest,helensch/ensembl-rest,ens-lgil/ensembl-rest,willmclaren/ensembl-rest,helensch/ensembl-rest,helensch/ensembl-rest,willmclaren/ensembl-rest