Fine-grained scrolling, bookmarks fixes

I'd like to propose merging the following changes to HexEdit:
* Enabling scrolling to work with mice that scroll in fractional increments (less than 120 ticks per message)
* Upgraded the projects to build with VS2013
* Fixed a number of issues around the bookmarks view:
 * Implemented the Add, Edit, and Delete buttons on the bookmarks toolbar
 * Fixed bookmarks in unopened files from showing up repeatedly
 * Fixed bookmarks in opened files never showing up at all
 * Fixed the bookmarks edit dialog not updating the color combo box upon open
 * Bookmarks can be deleted without opening their matching file (necessary for files that no longer exist)