Feature: locations for effectors

- add a combo of the locations available to the effectors, where needed
- TODO: improve usage/jsgui/src/main/webapp/assets/tpl/apps/param.html implementation
fix JS tests around location dropdowns, including defining String.trim for JS contexts where it does not exist
upgrade to jclouds-163 (pom only - other fixes needed and wanted, following shortly)
use new jclouds ImageChooser support to pick images far more intelligently!
override the GoogleComputeEngineHttpApiModule from 1.6.3 with a newer one in 1.6.x which supports more google identity formats (until 1.6.4 or 1.7.0 is available)
update PortableTemplateBuilder to work with jclouds-163 and jclouds-170
jclouds-163 code review tidies (comment and use guava)