Documentation: updated wiki
Fixed: Correctly reporting zoom levels

Previously the getPageDimensionsAtZoomLevel() was treating the page zoom level as 1-based, and not 0-based. This commit fixes this so that page zoom levels are treated as 0-based, and are capped at the maxZoomLevel() value.
Fixed: Missing semicolon
Fixed: JSHint recommendations
Fixed: flake8 visual indenting
Fixed: Multiple tiles loading when scrolling

Previously the isTileLoaded method was always returning false, so scrolling would continuously add tiles to the viewer.

This method reverts to an older method of checking whether a tile has been loaded.
Fixed: Highlighting wouldn't occur on page in the viewport

Previously the highlight plugin would highlight all pages but the first one.

This commit calls the highlight for the visible page after setting the highlight regions for all the pages.
Documentation: Documenting highlight plugin
Fixed: Highlights demo removes highlights before adding new ones.
New build
Formatting
Merge remote-tracking branch 'origin/master' into develop