curl legacy loader

Former-commit-id: 08c7c76abe03823e3cdb0e25f76c969fa073226e
Use `location.host` in test/index.html and test/underscore.html.

Former-commit-id: 34dd4860b7b83ec9b96b3f9062654bdf960ff75f
Rework the doc example for `_.after`.
Add @phated to the contributors in package.json. [ci skip]
Update repo links in readme. [ci skip]
Remove lesser used `backbone` and `legacy` builds from the npm package.
Use `truey` instead of `truthy`, /ht @brucelawson. [ci skip]
Move curl.js.
Remove legacy and backbone builds from dist/.
Cleanup dot (.) files.
Correct repo links in contributing.md.
Remove mobile builds from /dist/ as their in cons.