Navigation: Correctly (un)escape data-url all throughout the code

Also removes code dealing with nested list URL tokens (subPageUrlKey)

The initial bug was regarding the need to use selector-escaping when looking
for pages inside the DOM via their data-url attribute, because the the data-url
may contain "weird" characters like parantheses, single, and double quotes.

During the process of fixing this it became clear that the data-url attribute
can sometimes end up having a URL-encoded value - but not always. This makes
proper string comparison, much less selector-escaping, impossible. So, it
became necessary to require that data-url never be url-encoded.

Conversely, the URL that ends up in the location when using replaceState() must
be URL-encoded, otherwise, upon deep linking, one may end up with an invalid
URL. For example, if the URL contains an actual percent sign, and the URL is
placed in the location via replaceState(), the percent sign must be URL-encoded
in order for deep-linking to work.

Below are the original commit messages that have been squashed:

Pagecontainer: Escape dataUrl when trying to find page based on it
Navigation: Make sure location is encoded when going to a funky page
Pagecontainer: Test that _find() throws not when looking for weird URLs
Init: Correctly assign data-url for initial page
Init: Make sure "data-url" attribute for initial page is decoded
Pagecontainer: Decode URI when assigning to "data-url" during _parse()
Pagecontainer: Use decoded URL to build selector for data-url
Pagecontainer: Call convertUrlToDataUrl() via _createDataUrl()
Path: Always uri-decode when computing dataUrl
Pagecontainer: Remove extra decoding step, now part of _createDataUrl()

This also removes the possibility that a URL gets double-decoded.
Pagecontainer: Test behavior of _find() in the face of weird URLs
Navigation: Use data-url retrieved from Ajax request in its encoded form
Pagecontainer: Pass encoded URL to $.mobile.navigate()
Init: Rename JS file with spaces in it

(cherry picked from commit e4121024ee17856174c617f8c1bca7b322229c52)

Closes gh-7474
Fixes gh-1383