little face-lifting

- new hammer.js version
- tweak h1, h2, ul margins and line-height for advanced theme
- detect ipad as potential touch device
move jquery to the head (enable custom js for instances)
update hash, make text selectable, remove special css
misc changes

- enable simple page structure (no need for <div class=slide>)
- add button to close nav-controls
- tweak transition durations
- change a to open external links in target _blank
- add way to include custom header content (css, js, meta)