fix($resource): prevent default params to be shared between actions

Having a $resource defined as:

var R = $resource('/Path', {}, {
  get: {method: 'GET', params: {objId: '1'}},
  perform: {method: 'GET'}
});

was causing both actions to call the same URI (if called in this order):

R.get({}); // => /Path?objId=1
R.perform({}); // => /Path?objId=1
fix($cacheFactory): return undefined when removing non-existent entry

Instead of throwning an exception, remove should return undefined when
cache entry to be removed doesn't exist.

Closes #1497
feat(linky): allow optional 'target' argument

Closes #1443
fix($http): config.param should expand array values properly

Today, calling e.g. $http(url, { params: { a: [1,2,3] } }) results in a query
string like "?a=%5B1%2C2%2C3%5D" which is undesirable. This commit enhances
buildURL to createa query string like "?a=1&a=2&a=3".

BREAKING CHANGE: if the server relied on the buggy behavior then either the
backend should be fixed or a simple serialization of the array should be done
on the client before calling the $http service.

Closes #1363
feat($cacheFactory): cache.put now returns the added value

This allows common programming patterns to be expressed with more
concise code.

See #1583 for code examples.
docs(api): add ngRequired to input/select/textarea directives

Closes #1202
docs(README.md): fix "API Docs" link

use direct link to api docs
fix(Scope): allow removing a listener during event
docs(CONTRIBUTING.md): add contrib info file for GitHub
chore(jquery): upgrade to jquery 1.8.2
feat(jqLite): add triggerHandler()

we need triggerHandler() to become jQuery 1.8.x compatible.

this is not fully featured triggerHandler() implementation - it doesn't
bother creating new DOM events and passing them into the event handlers.

this is intentional, we don't need access to the native DOM event for our
own purposes and creating these event objects is really tricky.
fix(jqLite): fire $destroy event via triggerHandler

in jQuery 1.8.x the data() data structure is changed and events are
not accessible via data().events. Since all we need is to trigger
all event handlers, we can do so via triggerHandler() api instead of
mocking with the internal jQuery data structures.

This fix was originally proposed by PeteAppleton via PR #1512.

Closes #1512
fix(jqLite): support append on document fragment

previously jquery didn't support append on this node type, now it does
(since 1.8.x) so I'm adding this to jqlite as well.
feat(form): add ability to reset a form to pristine state

Retting a form to pristine state will cause all of the nested
form and form controls to be recursively reset as well.

Closes #856
test(ngRepeat): add test for issue #1076
fix(ngRepeat): attempt to simplify and improve existing fix for #933

I'm keeping this in for future reference. The issue with this solution
is that if we shift() the first item in the array, the whole repeater
DOM will be rebuilt from scratch, we need to do better than that.
test(ngRepeat): clean up and improve tests
fix(ngModel): sync ngModel state with scope state

In cases when we reuse elements in a repeater but associate
them with a new scope (see #933 - repeating over array of
primitives) it's possible for the internal ngModel state and
the scope state to get out of sync. This change ensure that
the two are always sync-ed up even in cases where we
reassociate an element with a different (but similar) scope.

In the case of repeating over array of primitives it's still
possible to run into issue if we iterate over primitives and
use form controls or similar widgets without ngModel - oh well,
we'd likely need a special repeater for primitives to deal
with this properly, even then there might be cornercases.

Closes #933
fix(ngRepeat): support mostly-stable repeating for primitives

I'm reverting changes that were originally done to ngRepeat to fix #933,
because these are now not necessary after the previous changes to keep
ngModel always synced with the DOM.
style(jqLite): better variable names

selector => cssClasses