swapping in bluebird, some promise cleanup
more refactoring to wrap entire async methods in promises
continuing to improve the promise method error handling
Related data constraint fixes
Add test cases for #97 - failed eager loading on parsed models

The ParsedPost model mutates its foreign key on `parse`, which causes
eager loading to fail to pair it to its parent. Non-eager loading (ie,
using #related instead of withRelated) is successful.
Parse eager-loaded models after pairing; fixes #97
Merge pull request #95 from lemonde/lmd-constraints

Related data constraint fixes
minor formatting tweaks
alias withRelated tables, fixes #96
Merge branch 'fix-#97' of github.com:benesch/bookshelf into benesch-fix97

* 'fix-#97' of github.com:benesch/bookshelf:
  Parse eager-loaded models after pairing; fixes #97
  Add test cases for #97 - failed eager loading on parsed models
test for morphTo parse, relation code cleanup
linking to docs for several Backbone methods, fixes #81
document columns option on fetch, fixes #100, #106
docs updates for 0.5.8
release 0.5.8
merging bluebird branch
using Promise.method throughout the library
swapping out underscore for lodash
Promise.method on eager fetch
bumping knex dep, updating Relations test output