Understanding Index: Fix typo

Fixes gh-471
Closes gh-485
jQuery UI Getting Started: Remove line number reference

Closes gh-484
Basic Plugin Creation: Cache jQuery object

Closes gh-482
Iterating: Fix typo

Closes gh-476
Manipulating Elements: Fix typo

Closes gh-467
Event Basics: Fixed typo

Closes gh-465
Getting Started: Fix reference to Firefox Developer Tools

Closes gh-461
Finding & Evaluating Plugins: Link to plugin registry

Closes gh-460
0.3.10
Conditional Code: Clarify what is truthy and falsy

Fixes gh-450
Scope: Fix explanation of variable scope

Closes gh-473
Closures: Fix typo

Closes gh-458
Selecting Elements: Fix typo

Closes gh-451
Closures: Fix a link

Closes gh-446
0.3.11
About jQuery: Link to various foundation pages

Fixes gh-74
Extending Widgets: Whitespace
Widget Factory: Fix data namespace and style issues

Fixes gh-274
Introduction to Events: Typo

Closes gh-383
Arrays: Remove `for in` example

Ref gh-321
Closes gh-385