Fix `which` parsing on Linux

[GoogleCodeExporter]

The GNU version of which outputs error messages as follows:

 $ which aaaaaa
 which: no aaaaaa in ...

This isn't handled correctly in lib/misc/file.

Attached patch adds an optional match for "which: " prior to "no ".

Original issue reported on code.google.com by JJC...@googlemail.com on 24 Feb 2015 at 4:23

Attachments:

• which.diff