Correctly specify source files

Forgive me if this is just user error and not a bug.

When opening a profile in `kcachegrind` (version 0.7.4), the source code view does not work with an error message that "no debug info is available".

Looking in the kgrind file, it seems that the function name is specified like:

```
fn=timeit /usr/lib64/python2.7/timeit.py:178
```

but this doesn't seem to be a supported format, according to this document:

```
http://kcachegrind.sourceforge.net/cgi-bin/show.cgi/KcacheGrindCalltreeFormat
```

This patch separates the function name from the file in `fl` and `fn` entries, which seems to fix the source code view.

I can't shake the feeling that I'm just missing something, though ;)