always create default users

For old notebooks, there was no default user
and so certain functionality such as documentation
would not work with recent sage.
This patch makes sure that the default users are
always created if they are not present.
French translation
Merge pull request #201 from fchapoton/master

French translation
Remove symbolic link
Move flask_version to inside sagenb
remove flask_version from sdist MANIFEST.in
Rename ../flask_version to flask_version in RU translation
make \color in MathJax behave similar to \color in LaTeX
Merge pull request #205 from ppurka/issue-205-mathjax-color

make \color in MathJax behave similar to \color in LaTeX
Update cell.py

Changed the URL that Cell.files_html() preppends inside jmol_script for the live help, from cell URL, to worksheet URL. See comments.
Merge pull request #208 from aghu/patch-1

Update cell.py to fix issue 179
Fix some minor typos
Provide a more informative message when source code can not be displayed

This happens for example when running the following:
import scipy
scipy.sin??
Merge pull request #209 from ppurka/issue-207

Provide a more informative message when source code can not be displayed
few more ../flask changes
Merge pull request #204 from ppurka/issue-203-flask

Move flask_version directory
Doctest fix for sphinx 1.2
Update settings.py

Make 'settings_page' function check password and e-mail for validity as required by the 'login' function in authentication.py
for the password.
Merge pull request #217 from kapilhp/patch-1

Update settings.py to ensure that change in user password and email address gives proper error messages.
update instructions for modifying sagenb in HACKING.rst