[Fix] Hint Labels no longer appear on top of input text boxes

- This applies to cases where there are links directly under
the input text boxes (and which are occluded by the text boxes)
[Feature] selectAnyLink: Remove hints that don't match

The aim is to let hints be used with the min. amount of page cluttering
[Feature] selectAnyLink - Hints: Once an exact match is found, hide it's hint

- This is done to prevent (part of) the element being occluded by the
 hint (which something I greatly disliked about hints in Vimium etc.)
[CSS] SelectAnyLink: Make the selected link easier to spot

- Make the selected (green) link easier to find in the midst of
all the matched (yellow) links by making the green at bit darker
and the yellow lighter.
[Feature] selectAnyLink In-progress: some fixes + minor refactoring
[Feature] selectLink (in-progress): Use arrays instead of jQuery sets for better performance

- Gnerating a collection of elements using jQuery's add() creates
a new jQuery object each time it is called, so arrays should be faster
[Feature] selectAnyLink: Fix issue of UI closing on clicking right part of the main textbox

- This was happening due to the 'count' span (which was positioned on
the right part of the main textbox getting clicked, and being
non-focusable itself, leading to the entire UI losing focus, and
thereby closing (at it is meant to on losing focus).
[CSS] Minor
[Feature] selectAnyLink - in progress
[Feature] selectAnyLink in progress
[Feature] Closes #103
[Feature] selectAnyLink - mostly completed! (more than) closes #63 !

- Enabled quick switching between main text and hint text inputs using
 space/shift keys -- this ties the whole UI together.
- Some other misc changes
- (Some issues still remain, but feature mostly usable now)