Trying to fix tiddler title slash issue using double escaping in TW5 tiddlyweb plugin

I am experiencing issues saving tiddlers with slashes from TW5(5.1.5-prerelease be2a74d623b6cef4516bcd146d84ec82294c7ae6) to TiddlyWeb. 

I get 404 responses from the server.

I decided to use the hint from https://mail.python.org/pipermail/web-sig/2008-January/003135.html :

> If you really want PATH_INFO to have "%2F" instead of "/", then I suggest encoding the slashes as "%252F" or "$2F" or something else. Then your application will be portable.

I do not know if it is relevant anyhow, but I tried to solve my issue that way (escape the `/` twice) and it worked.

I use `twanager server` command to start the server (`wsgiref`) and do not use `tiddlywebwiki`

```
Python 2.7.8

This is TiddlyWeb version 2.3.0.
    The current store is: tiddlywebplugins.mysql3 (3.1.2).
System Plugins:
        tiddlywebplugins.status (0.8)
        tiddlywebplugins.logout (1.0)

MySQL-python==1.2.5
SQLAlchemy==0.8.7
html5lib==0.999
httpexceptor==1.3.1
pyparsing==1.5.7
python-mimeparse==0.1.4
resolver==0.2.1
selector==0.10.1
simplejson==3.6.5
six==1.8.0
tiddlyweb==2.3.0
tiddlywebplugins.logout==1.0
tiddlywebplugins.mysql3==3.1.2
tiddlywebplugins.sqlalchemy3==3.1.1
tiddlywebplugins.status==0.8
wsgiref==0.1.2
```