XML nodes are ordered. Closes #441.
Python 2.6 doesn't support OrderedDict from stdlib

So I had to add support for the back-port version. Addresses #441.
New test also runs with Python 3. Addresses #441.
Make concurrency checking optional during get_document()
Item _internal functions
Kevin Funk
Comma delimited sort syntax.

You can now use something like ?sort=lastname,-age as an alternative to
MongoDB syntax.

Closes #443. It takes a slightly different approach than the original PR
though, as the changes are all introduced at the Mongo data layer level. This
allows future data layers to parse the sort syntax as desired.
tox positional arguments
Merge branch 'internal-methods' of github.com:k-funk/eve into k-funk-internal-methods
update docstrings for put and deleteitem
Merge branch 'internal-methods' of github.com:k-funk/eve into k-funk-internal-methods
Kai Danielmeier
add some _internal unit tests + payload in headers of put/patch
fix additional lookup regex
Ashley Roach
Fix regex in RESTful Account Management tutorial
Merge branch 'aroach-develop' into develop
Merge branch 'internal-methods' of github.com:k-funk/eve into k-funk-internal-methods
post_internal, patch_internal, delete_internal
Merge branch 'k-funk-internal-methods' into develop

Conflicts:
	CHANGES