Backend user auth, user service, and misc gruntfile and gitignore changes

Here's the summary:
-added jwt_auth
-added passport
-added base64 encoding to submission on mymeets_routes_test
-backend tests pass
-added more files to gruntfile jshint and jscs linters: lib, tests, gruntfile; linters won't lint /build or testbundle
-added /build, /data, and testbundle to gitignore; removed testbundle from git control
-moved some of the login controller stuff into userservice
-added an error handling test to the front end user tests
-all front end tests pass