Update link_to.js

add description for `disabled` and `disabledWhen` properties for `link-to` handlebar helper.
Removes long-deprecated getPath/setPath
Merge pull request #3344 from c0urg3tt3/patch-4

Update link_to.js
Merge pull request #3350 from trek/remove-getPath-setPath-deprecations

Removes long-deprecated getPath/setPath
[BUGFIX beta] ReduceComputedProperty ignore invalidated property observers.

It can happen that several reduce computed properties depend on the same items,
because the same items are shared between computed arrays.  This will often be
the case with filter/sort chains, for instance.  When they depend on the same
item properties it can happen that an item property change is registered for a
downstream array, but a different item property observer invalidates the change.

For example, changing the priority on an item may cause it to be resorted.  This
resorting will result in it being removed and reinserted into a downstream
filtering.  However, the original priority change also triggered an observer to
update the filtering: an observer that has been invalidated by the changes
resulting from its being resorted.

- Properly invalidate such observers.
- Also update indexes even more lazily, during `flushChanges`.

Fix #3273.
Fix silly !!!! boolean conversion.
[FEATURE reduceComputedSelf] reduceComputed dependent keys may refer to @self.

This is mostly useful for array proxies, and in particular array controllers
that use item controllers.  This allows users to, for instance, sort items
according to properties specified on array controllers.

@self is implemented only in reduceComputed because it doesn't really make sense
for non-reduceComputed CPs.

Thanks to @tchak for pointing out the need for this.
Merge pull request #3364 from hjdivad/fix-3273

ReduceComputedProperty ignore invalidated property observers.
Merge pull request #3365 from hjdivad/reduce-computed-self

reduceComputed dependent keys may refer to @self.
[FEATURE query-params] Adjust query params param order
Merge pull request #3383 from alexspeller/query-params-adjust-param-order

Adjust query params param order