sanitize rating comments
Merge pull request #323 from migeruhito/rating_comments

Provisional workaround to sanitize rating comments
Move babel import inside function
Update Sagenb version to 0.11.2
Update instructions to use GNU tar

This should at least partially fix Sage Trac 17490.
Correct localization information

This is not a full answer to #313 but is a start to making this information correct.
Update release instructions

Adding any relevant stuff from old release instructions,
mainly to remind of prerequisites.
Remove outdated instructions

(From the readme)
startup code beautify
Exception check fix
Unused variable deleted
Simplify some path manipulation
import cleanup in startup code
Delete unused variable in notebook startup tests
Proper explicit definition of methods in startup code
Test function moved to misc.misc
test module function in misc.misc
test module used in startup code
test module used in notebook
sagenb.notebook.notebook imports cleanup and side effects on import sagenb.notebook.config removed