[docs] Minor Change to method doc block
missing period
Merge pull request #4953 from alexquiambao/4.2

missing period
Merge pull request #4952 from alnutile/patch-1

[docs] Minor Change to method doc block
Fix logic around marking services resolved or not

If you app->extend an object after it's been bound but before it's
been resolved, it will be initialized right away. The solution is
to just check if an object has actually been resolved rather than
if it's bound.

A related issue that can also be solved as a part of this is that
you can't extend deferred services. This has also been fixed.
tests for 3841d39