Upgrade sagenb to 0.6

[TimDumol]

I think the title says enough.

Here's the log:

#7801 Alex Leone: Notebook saves twice on exit [Reviewed by Tim Dumol]
#2779 Tim Dumol and Willem Palenstijn (ref. patch): Error message for notebook server already running is misleading [Reviewed by Willem Palenstijn and Tim Dumol]
#7835 Tim Dumol and Mitesh Patel (ref. patch): Preparsing on server does not account for unicode text [Reviewed by Mitesh Patel and Tim Dumol]
#7666 Mitesh Patel: Alphanumeric cell IDs, resize on Paste, ESC ends introspection, JSLint for notebook_lib.js [Reviewed by Tim Dumol]
#7858 Mitesh Patel: Add Content-Type to JS and declare KEY_* vars [Reviewed by Tim Dumol]
#7874 Mitesh Patel: jsMath.Process() interact controls' labels [Reviewed by Tim Dumol]
#7863 Mitesh Patel: Declare vars, remove lint from auxilliary JS files [Reviewed by Tim Dumol]
#7786 Tim Dumol and Mitesh Patel (ref. patch): Restructure templates to idiomatic Jinja [Reviewed by Mitesh Patel and Tim Dumol]
#7847 Tim Dumol: Emptying the trash in Firefox 3.5.6 displays a "Forbidden No referer found. Forbidden." page [Reviewed by Mitesh Patel]
#7663 Mitesh Patel: Don't rstrip internal prompt in expect.py [Reviewed by Tim Dumol]
#7648 Mitesh Patel: Issue with indentation of first line being wrong [Reviewed by Tim Dumol]
#7937 Mitesh Patel: Add sass directory to MANIFEST.in [Reviewed by Tim Dumol]
#7650 Mitesh Patel: Fix doctesting under sagenb [Reviewed by Tim Dumol]

It's up at http://boxen.math.washington.edu/home/timdumol/sagenb-0.6.spkg

Component: notebook

Author: Tim Dumol, William Stein

Reviewer: Robert Miller

Merged: sage-4.3.1.rc1

Issue created by migration from https://trac.sagemath.org/ticket/7994

[rlmill]

Author: Tim Dumol, William Stein

[rlmill]

Reviewer: Robert Miller

[rlmill]

Merged: sage-4.3.1.rc1