ENH: ensure some visible space between log elements

Sometimes (like coder output window) a tab \t has no visible extent
despite there being a tab char. so you can get things running together:
0.1435  INFOencrypt: destroy()ed original file (secure delete)

The change ensures that there is some whitespace, like:
0.1279  INFO encrypt: destroy()ed original file (secure delete)

For me this makes DEBUG and INFO columns line up a lot more read-ably.

Note: maybe some people parse their log files in a way that splits on \t
and the trailing space would now mess them up? probably very few people
Merge pull request #370 from jeremygray/master

ENH: ensure some visible space between log elements