A serializer implements `extractEmbeddedData` to retrieve embedded
associations data
fix path issues for upload to s3

i am an idiot. :)
Merge pull request #972 from fivetanley/patch-1

fix path issues for upload to s3
resolveWithEvent -> resolveOn
Merge pull request #974 from tchak/resolve-on

resolveWithEvent -> resolveOn
ignore bundle directory (for standalone bundling)
bump ember-dev
cleanup gemfile
don't rely on native forEach and consistency
do not try to clear relationship when there is no inverse
Merge pull request #977 from sly7-7/many-to-none-fix

do not try to clear relationship when there is no inverse
Check against `null` and `undefined`
continue ember-dev cycle fixes, and also bump ember-dev
Rename none/empty to isNone/isEmpty variables

Rename none ti isNone and empty to isEmpty variables. It makes the code
easier to read.
Merge pull request #981 from karlguillotte/master

Rename variables none/empty to isNone/isEmpty
Ignore 'docs/node_modules'

`yuidoc` is installed into this directory.
Avoid incorrect tag warning

```
warn: (docparser): replacing incorrect tag: returns with return:
```

I rewrite `returns` -> `return`.
Merge pull request #985 from tricknotes/avoid-incorrect-tag-warning

Avoid incorrect tag warning
Merge pull request #984 from tricknotes/ignore-node-modules

Ignore 'docs/node_modules'
Simplify not-null-or-undefined check