Fix fragment inclusion when fragment === 'body'

In the case where 'body' was specified as the fragment the $fragment variable already pointed to the list of child nodes for the body so calling .contents() gave back the second level of descendents instead of the desired first level.
update unit test with new expectation to include body fragment direct children
Add support for file input fields
Only use FormData() for POST requests
Fix typo in README.md, "Layout Reloading" section
Merge branch 'before-replace'

Fixes #383, closes #384
pjax 1.9.0
Ignore gemfile
pjax 1.9.1
Ensure pjax.state is consistent before pjax:beforeReplace event
Add previous state to beforeReplace event
Move state and previousState to event props
Fix previousState scope to success closure
Merge pull request #403 from defunkt/before-replace-event-tweaks

Before replace event tweaks
pjax 1.9.2
Trim cache length in cachePop, not just cachePush

This fixes a bug where the `pjax.defaults.maxCacheLength` setting was
being applied when navigating to new pages but not when users hit the
back or forward buttons.

Two symptoms of this were:
* Setting `maxCacheLength = 0` didn't completely disable caching;
  hitting the back button followed by the forward button would ask the
  server for the first page but read the second one from the cache. I
  think this is probably the bug that was discussed on issue #406.
* Regardless of what you set `maxCacheLength` to, the forward cache
  would continue growing as long as you kept hitting the back button.
Split up and simplify maxCacheLength tests

A few changes to make these tests less scary:
* Invert `navigationWasCached` var to `didHitServer`, which feels a
  little more intuitive.
* Split the back button and forward button cases into separate tests.
* Reduce the number of assertions per test.
* Replace some comments with assertion text.
* Reduce `maxCacheLength` in the back button and forward button tests
  from 2 to 1 so that each test requires fewer steps.
Fix curl download instructions

curl needs to follow redirects in order to fetch the raw file.
Improve pjax function synopsis and :memo: the options
Merge pull request #433 from defunkt/options-docs

Document the pjax options