Add page selection menu

[ongsalt]

related #5518
On mobile when click at the page number the page selection menu will show up. On desktop this menu can be trigger using ... button in pagination instead.

I also add Utility.isMobile to determine user platform based on screen size similar to css .mobile-only

[BrokenEagle]

Yo man... you're going to want to squash this down to a single commit to have any hope of this ever being merged.

[ongsalt]

Yo man... you're going to want to squash this down to a single commit to have any hope of this ever being merged.

Done. I'm kinda new to this may I ask why. Also I don't know if i should include b41563b or not

[BrokenEagle]

Yeah, don't include b41563b. If any merging needs to be done, evazion can do it on his side. However, if there are any merge conflicts, then you'll have to resolve them yourself and update the commit.

As for why this is done, it's cleaner and easier to follow. Basically, each commit should encapsulate one entire change to the system, whether it's a minor fix or a feature add. If a pull request has multiple new features and/or changes, then it's fine to break them up each of them up into their own separate commits.

[ongsalt]

Is this okay?

[BrokenEagle]

For the Utility.isMobile function, use the window.screen variable instead, so as not to falsely identify browers on desktop computers which have had their widths shrunk beneath the 660px cutoff.

Utility.isMobile = function () {
  window.screen.width <= 660 || window.screen.height <= 660;
}

I went and added a check for the height as well, since many of your newer devices have a screen height greater than 660, in which case it would falsely detect it as being a desktop when the user has the phone rotated horizontally.

It's outside the scope of this PR, but the mobile CSS should probably be updated to reflect that as well.

/**** Mobile-only CSS ****/
@media (max-width: 660px) and (max-height: 660px) { } 

[ongsalt]

As for screen height. There are a lot of place where @media (max-width: 660px) is use. I don't know if changing any of this will break something else.