First refactoring
Remove section attribute implementation.
Fix element attributes, except for multi-line.
Fix previous element selection.
Removes console.log calls.
Simpler default syntax for markdown attributes.

- on slides: .slide x=y
- on elements: .element x=y

Those are detected in html comment, in order to not be visible
if a markdown is edited in an html editor.
test-markdown-attributes.*, new default separator

- Reformat.
- Change default separator test 'slide: x=y'
test-markdown-element-attributes: formats and test.

- Reformat
- Use new default separator format: '.element: x=y'
- Add new tests for testing that default format
README.md mentions the new default separators.

- new default separator for slide attributes
- new default separator for element attributes
Illustrate both, in html comments.
Merge branch 'attributes' of https://github.com/VonC/reveal.js into dev
readme correction for #734
add example of markdown slide and element attributes
rename markdown attribute test files to same format
2.6.1 #734
add instructions to features that require a local web server (closes #732, #673, #559)
The index.html page had the simple theme listed twice. The duplicate was removed.
For the Moon and Solarized themes they had .css appended to them which was causing them to not come up.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	index.html
Add a different index.html page and add instructions