Add information about generating keys

We didn't say what `secure=True` does about keys, and given the likelihood of things like https://groups.google.com/forum/#!topic/sage-support/zglN_3QLCPo happening again in the future, it is a good idea to document this better.

HT to Jori Mäntysalo for this placement and essentially the wording.
Set platform speed to 8

This will enable rotating plots to maintain all their attributes, at the expense of some slowdown for very large plots on certain slower platforms.
Add jsmol to the allowed commands for public worksheets
Path name for live documentation jmol files, fixes #256
Merge pull request #257 from sagemath/3d_live_documentation

3d live documentation

Whitelist jsmol as a command and fix directory typo.  Closes #256
Remove superfluous if/then in template

We couldn't have gotten to this spot if this condition weren't already true from the previous if.
Re-enable new compute cells in live documentation

This brings back previous behavior (and removes the text cell icon since we don't want that) in the live doc.  
Note that the only way to get the new cell will be clicking the actual icon, but that is okay in the docbrowser context and can be documented.
Re-enable last new compute cell in live doc

This brings back previous behavior (and removes the text cell icon since we don't want that) in the live doc.  
Note that the only way to get the new cell will be clicking the actual icon, but that is okay in the docbrowser context and can be documented.
Update notebook_help for new icons

The jsmol changes brought some new icons and behavior as well.
Also adds a few needed documentation things.
Reorganize misc parts of README

Just making things a bit clearer
Updated Release Manager Instructions
Finalize release instructions

Also fix a few other minor notes in README
Add more developer instructions to README

In particular, to HACKING.rst
Merge pull request #259 from kcrisman/releaseinstructions

Include correct release instructions
dist.sh: Remove all sagenb stuff from dist/ dir on -s arg
Remove unneeded rm

This is already done in the script itself.
Add info on 'sage -f' when needed
Even more minor release instruction fixes
Update Sagenb version to 0.11.1
Merge tag '0.11.1' into release