docs(guide/directive): rephrase for consistency

- referring to `=attr` rather than `=prop` is consistent with note under example with =customerInfo
- change `prop` to `attr` (basically `prop` refers to property in JS object, `attr` is for HTML tag)
- change the function name in description to match the name in code example

Closes #5786
docs(README): fix typo

Closes #5813
docs(ngShowHide): make a note of values considered to be falsy

This issue has been a focus of problems for some users and we discussed it on the IRC that it should
be at least documented.

~Amended the style to use bootstrap notes, I think overall it looks better and catches the eyes more
easily. However there are no anchor links to these, if these are necessary they can be added later.

Closes #3436
Closes #5762
docs(concepts): fix typos in explanation

Code uses module names with '2' as suffix while the explanation used the module names without the
suffix. The diagram is correct but also does not suffix the module names.

Closes #5567
docs(tutorial): reference node command before scripts\web-server.js

Amended to also clarify this note in the mac/linux tab.

Closes #5845
docs(animations): renamed animate-show-hide to sample-show-hide

This always throws me off - I think it helps to make it clear that the class name is arbitrary, and
what matters is the .ng-etc classes.

Closes #5848
docs(tutorial): fix typo

Correction misspelling: easist -> easiest

Closes #5850
docs(tutorial): add missing semicolon to code snippet

Lets encourage people to use semicolons in javascript :>

Closes #5834
docs(contributing): add instructions to install grunt-cli/bower globally on unix systems

Closes #5814
Closes #5811
docs(ngChange): clarify difference between ng-change DOM change event

The ng-change event triggers immediately, which makes a difference for text input fields and text
areas, where the JavaScript onchange event would only be called at the end of the change.

Closes #5640
docs($sce): correct documentation for angular 1.2.0

Include mention of `ngSanitize` (and add it to the example), as well as removing (and clarifying if
needed) references to `ng-html-bind-unsafe`.

Closes #5551
docs(input): document ngValue directive

Extend the example with ng-value showing how to deal with default checked radio boxes.

Closes #5654
docs(api): adds links to top level guides

The main api docs page is probably the main landing page for many devs
looking to learn angular, so linking to the main guide pages would
likely help.

Closes #5869
docs(directive): link to directive registration api function

Originally, this issue was regarding documenting `restrict: 'CM'` in the directive guide, but it
was pointed out that the restrict documentation is covered in the $compile documentation. Because of
this, a link was simply added to the $compile documentation.

However, the wording suggests that it's actually linking to the directive registration function, in
$compileProvider, so the docs will link there instead. There is a link only a paragraph below to the
$compile documentation, so this does not hurt.

Closes #5516
docs(services): use $log service in example consistently with $log API

The $log provider returns an object and not a function, so this example, which appears to be using
the $log provider, should call it as it would be called in a real-world application.

Closes #5875
docs(ngInit): note precedence when used with filters

Clears up expression priority issue

Closes #3869
Closes #5873
docs(ngInit): ng-init is an attribute/class directive, not an element directive

As discussed in comments on https://github.com/angular/angular.js/commit/42ec95ebae716c81087684b55ed8fa8c13888abc#commitcomment-5109829,
ngInit is not an element directive, so @clkao's example should reflect this.

Closes #5879
docs($q): note that function okToGreet is expected to be defined in example

the function okToGreet wasn't defined, so this example wouldn't work properly.

I've decided that instead of adding unrelated code to the example, it should just be noted that the
function is expected to be defined in the lexical scope.

Closes #5878
docs($provide): fix Markdown formatting for provider method

Indentation made Markdown parser think that it’s a block of code.

Closes #5446
docs($http): remove outdated part about $http outside of $apply phase

This removes some outdated advice which no longer is true against the latest angular version.

The information about unit testing with ngMocks remains, because it's always good to have
information like that easily found. This little snippet is not worded perfectly, and is not
a very good example unit test, so additional work is needed here.

Relates to #5206
Closes #5485