Implement a scrolling pager

Very first go. Still with known todos and debugging code, but let's see if we can have a starting point.

This introduces a new theme: 'pagerer_scrollpane', and a new 'Current page' display option: 'scrollpane'.

So #1 is committed and pushed to 7.x-1.x-dev, but this still needs work.

Follow-on: fixed logic for allocation of scrollpane buttons in .module.

#3 committed and pushed to 7.x-1.x-dev.

Follow on:
- fixed scrollpane anchors width for item ranges
- simplified scrollpane pager shift logic

#5 committed and pushed to 7.x-1.x-dev

Follow on:
- fixed scrollpane shift to first/last
- use a state variable object rather than Drupal.settings

#7 committed and pushed to 7.x-1.x-dev

Follow on:
- removed css transition in favor of jQuery animate
- fixed scrollpane border color
- queueing of subsequent button clicks still NOT working

#9 committed and pushed to 7.x-1.x-dev

Follow on:
- queueing of subsequent button clicks now works

#11 committed and pushed to 7.x-1.x-dev

Follow on:
- button process exit immediately if button disabled

#13 committed and pushed to 7.x-1.x-dev

Follow on:
- clear queue if button pressed in direction opposite to current spin

#15 committed and pushed to 7.x-1.x-dev

Follow on:
- implemented acceleration of shift in fastScrolling

#17 committed and pushed to 7.x-1.x-dev

Follow on:
- implemented separators

#19 committed and pushed to 7.x-1.x-dev

Follow on:
- fixed handling of anchors in views
- added documentation
- code cleanup

Committed and pushed to dev.