docs(srcset): fix mistake in example
docs(guide/introduction): use durandal as an example of a framework

To me knockout is a library that does data binding well.
Durandal is a framework that uses knockout as it's data binding component.
docs(guide/unit-testing): correct spelling
chore(ngMock): replace misplaced comma with semicolon
docs($q): remove unnecessary $scope.apply wrapping

As of Angular 1.2, this kind of thing is no longer necessary (thank goodness!)
fix(core): drop the toBoolean function

So far Angular have used the toBoolean function to decide if the parsed value
is truthy. The function made more values falsy than regular JavaScript would,
e.g. strings 'f' and 'no' were both treated as falsy. This creates suble bugs
when backend sends a non-empty string with one of these values and something
suddenly hides in the application

Thanks to lgalfaso for test ideas.

BREAKING CHANGE: values 'f', '0', 'false', 'no', 'n', '[]' are no longer
treated as falsy. Only JavaScript falsy values are now treated as falsy by the
expression parser; there are six of them: false, null, undefined, NaN, 0 and "".

Closes #3969
Closes #4277
Closes #7960
revert: chore($resource): refactor confusing case statement

This reverts commit d50829bcf74318a02bbfdbd3172a2bfb95b9283d.

This commit introduces a regression that results in urls with
parameters being incorrectly generated. We need to investigate
further why this is happening, for now I'm just reverting.