Better ContactStore.contact_for_addr() non-existent contact handling
get() and get_or_create() api methods for jsbox contacts resources
update() api method for jsbox contact resource
new() api method for jsbox contact resource
Merge branch 'develop' into feature/issue-211-contact-management-for-jsbox
Better error handling for ContactStore and contacts jsbox resource
Unicode tests for jsbox contacts resource
Merge branch 'develop' into feature/issue-211-contact-management-for-jsbox
Merge branch 'feature/issue-211-contact-management-for-jsbox' into develop