Removing .jshintrc file from Fieldbook source. New standards are hosted at https://github.com/goodforenergy/javascript, and it is suggested you place the .jshintrc file at the root of your source directory, so all your projects will inherit the same settings.

Issue: none
Reviewer: none
Removing fieldbook-tree.js, whose methods are not used anywhere.

Issue: GCP-8822
Reviewer: Rebecca Berrigan