Plugin Creation: remove content regarding utility methods
Fixes gh-396
Closes gh-577
0.4.2
All: Capitalize 'Ajax' correctly
Closes gh-583
0.4.3
Events: Added heading
Closes gh-532
Update advanced-plugin-concepts.md

Comment should be above the code for consistence with other pages.
0.4.4
Advanced Plugins Concepts: Fix context meaning

`this` in the `showNextImage` function is a reference to `nextButton` and
not as stated to the image node

Closes gh-525
Fixes gh-514
Intro to Events: expand MDN

MDN is not a well known abbreviation, and therefore in this context
should be expanded (at least the first time it is used).

Closes gh-531
Understanding Index: Add note on <1.9 bug

Talk about why we use `.first()` in the examples.

Closes gh-582
Fixes gh-276
javascript-101/operations: Clarify comment

Adding quote around an console.log output clarifies that it's
actually a string. In this article this really makes sense.

Closes gh-581
Fixes gh-542
Merge branch 'master' into object-additions

* master:
  javascript-101/operations: Clarify comment
  Understanding Index: Add note on <1.9 bug
  Intro to Events: expand MDN
  Advanced Plugins Concepts: Fix context meaning
  0.4.4
  Update advanced-plugin-concepts.md
  Events: Added heading Closes gh-532
  0.4.3
  All: Capitalize 'Ajax' correctly Closes gh-583
  0.4.2
  Plugin Creation: remove content regarding utility methods Fixes gh-396 Closes gh-577