Prevent error when renaming outliner titles
This is an attempt to resolve #2. The walkback occurs due to
the categoryList in the pluggable outliner being empty. The
existing code attempts to get the last element and the index of
it and fails.

This fix first checks if the categoryList is empty and then stops
the editing process. The walkback no longer occurs. Unforunately
the title of the object doesn't change either. It immediately
goes back to what it was originally.
Added "New Object" to desktop menu.

Every video I watch of self being demonstrated, old or new, starts
with creating a shell, spawning "()", and then closing the shell. Why
not make that a menu item since it is an obvious pattern?
Added section numbering to langref.rst

added section numbering as it is used heavily in the text.
.. sectnum::
   :depth: 3
   :start: 1
   :prefix: 2.
Fix to URL links to handbook in readme.md
Merge pull request #35 from spdegabrielle/patch-2

Added section numbering to langref.rst
Merge pull request #31 from zenspider/new_object

Added "New Object" to desktop menu.
Merge pull request #18 from doublec/outliner_issue2

Prevent error when renaming outliner titles
Bump date on legal/LICENCE
Merge branch 'master' of github.com:russellallen/self
Webserver code removed to separate repo
Fix a typo.
Remove serverDemo binary files
Fix serverDemo C code to compile under Linux
Fix bitrot in serverDemo Self code
Fix bitrot in applications/pep
Handle hex and invalid entities in HTML pages
Fix typo in JPEG image builder method name
Merge pull request #42 from doublec/webbrowser

Webbrowser fixes
Merge pull request #41 from doublec/serverdemo

Fix bitrot in serverDemo code
Merge pull request #39 from rrthomas/master

Fix a typo in handbook.