[Documentation] typo in `find` documentation
Merge pull request #2197 from locks/patch-2

[Documentation] typo in `find` documentation
Added documentation for preload parameter

Documented the purpose of the `preload` parameter on the `find` and `findById` functions
Update model.js
Merge pull request #2199 from gslot/patch-1

Update model.js
Added an example of how to use the preload arg

As per @bmac's suggestion to swipe the example from system/model.js's _preloadData function
Fixed typo

Fixed typo caught by @chrisvariety
Fixed typo

Fixed typo caught in https://github.com/emberjs/data/pull/2198
Don't use the DOM in the store tests

Using the DOM in the store test was breaking the build on Travis due to Runloop complaints.
There really isn't a reason why the DOM use is needed, so I refactored
the test instead of messing with the Runloop.
Merge pull request #2203 from emberjs/fix_travis_build

Don't use the DOM in the store tests
Merge pull request #2202 from ctataryn/patch-2

Fixed typo
modelFor is used constantly, the extra normalization and string splitting was causing measurable slowdown.
Merge pull request #2204 from stefanpenner/speed-up-model-for

modelFor is used constantly, the extra normalization and string splittin...
name some common anonymous functions
small perf, this map was unfortunately adding 5ms -> 8ms overhead for pushMany of N=1000. Removing it removed the overhead entirely.

Maybe at some point runtimes will actually optimize this…
Merge pull request #2207 from stefanpenner/small-perf

small perf, this map was unfortunately adding 5ms -> 8ms overhead for pu...
Removed a duplicate explanation of preload

Removed what is essentially a duplicate explanation of `preload` as per @igorT
Updated docs to warn against use of async:true with EmbeddedRecodsMixin
Merge pull request #2198 from ctataryn/patch-1

Added documentation for preload parameter
remove unused variables and enforce in jshint

fixes GH-2209