Test and document native order

[vweevers]

Closes #156. Reverts the temporary workaround introduced in #155.

Tested locally in Chrome, FF, Opera, IE and Edge.

Stumbled upon a curious bug in IE and Edge: if the database contains any key types other than string, then { gte: '' } yields 0 results. I've disabled the relevant test by commenting it out.

[ralphtheninja]

This is really cool!

[ralphtheninja]

Also really cool! :)

[vweevers]

Tests failed on what seems like an unrelated race issue (or conflict between tests, idk):

Click to expand

# add key after snapshotting that sorts first
ok 624 no open error
ok 625 no put error
ok 626 no put error
ok 627 no next error
ok 628 got a key
not ok 629 correct key
  ---
    operator: equal
    expected: 'z'
    actual:   'a'
    stack: |-
      Error: correct key
         at assert (http://airtap.local:37774/airtap/test-bundle.js:9389:9)
         at bound (http://airtap.local:37774/airtap/test-bundle.js:9241:21)
         at equal (http://airtap.local:37774/airtap/test-bundle.js:9549:5)
         at bound (http://airtap.local:37774/airtap/test-bundle.js:9241:21)
         at Anonymous function (http://airtap.local:37774/airtap/test-bundle.js:2255:9)
         at Anonymous function (http://airtap.local:37774/airtap/test-bundle.js:146:5)
         at Anonymous function (http://airtap.local:37774/airtap/test-bundle.js:27:788)
         at Item.prototype.run (http://airtap.local:37774/airtap/test-bundle.js:4476:5)
         at nextTick (http://airtap.local:37774/airtap/test-bundle.js:4447:7)
  ...
<MicrosoftEdge 18 on Windows 10> # add key after snapshotting that sorts first
Error: correct key
not ok 630 correct value
  ---
    operator: equal
    expected: 'from snapshot'
    actual:   'not from snapshot'
    stack: |-
      Error: correct value
         at assert (http://airtap.local:37774/airtap/test-bundle.js:9389:9)
         at bound (http://airtap.local:37774/airtap/test-bundle.js:9241:21)
         at equal (http://airtap.local:37774/airtap/test-bundle.js:9549:5)
         at bound (http://airtap.local:37774/airtap/test-bundle.js:9241:21)
         at Anonymous function (http://airtap.local:37774/airtap/test-bundle.js:2256:9)
         at Anonymous function (http://airtap.local:37774/airtap/test-bundle.js:146:5)
         at Anonymous function (http://airtap.local:37774/airtap/test-bundle.js:27:788)
         at Item.prototype.run (http://airtap.local:37774/airtap/test-bundle.js:4476:5)
         at nextTick (http://airtap.local:37774/airtap/test-bundle.js:4447:7)
  ...
<MicrosoftEdge 18 on Windows 10> # add key after snapshotting that sorts first
Error: correct value
ok 631 no run error
ok 632 no iterator end error

[vweevers]

Restarted the build.