[Qt-creator] Creator does not display correct icons for .c and .hpp files

[Daniel Price]

I use a mix of c and c++ code bases and I'm trying to use .hpp  
extensions over .h extensions for strictly c++ headers. I've noted  
that although Creator has a preference option for the suffix to use  
when generating files, it only displays a blank/generic file icon in  
the project list for .hpp and .c files, even though the OS (in this  
case OSX) recognizes them correctly.

I raised this as a bug using the feedback form along with some other  
issues but I'm not sure this went anywhere.