wiki pages with spaces in titles passed to custom script without delimiters

What steps will reproduce the problem?
1. use a custom wiki2html script, through 'custom_wiki2html`: ...
2. change syntax to 'markdown'
3. attempt to convert a page whose title has spaces to html

What is the expected output? What do you see instead?
I expect the filename of the page to be sent to the script within quotes, like 
this:
"/home/user/vimwiki/page with spaces.html"
but instead, it's sent like this:
/home/user/vimwiki/page with spaces.html

This makes parsing the full URI of the file impossible, and limits the titles 
of pages and links that you can make using vimwiki with a custom wiki2html 
script.

What version of the product are you using? On what operating system?
I'm using the lastest version with vim7.3 on osx lion 10.8.2

Please provide any additional information below.

That's pretty much it.  Doesn't seem like a big deal but it severely limits my 
options as a user.

Original issue reported on code.google.com by dan.cala...@gmail.com on 29 Nov 2012 at 4:10

vimwiki-backup / vimwiki

wiki pages with spaces in titles passed to custom script without delimiters #392