Calvin Buckley authored Aug 22, 2020 and Albert Astals Cid committed Aug 22, 2020

This lets you pick where the saved call graph visualization should
go, and what format you wanted it in. Previously, it generated a
dot file, and on Unix, a PostScript file. This lets you choose a
dot or PS/PDF file, rendering to an intermediate dot file if needed.

This also changes the context menu in the per-function graph too,
increasing commonality in code.

More formats can be added as needed.

Possible caveats:
- QProcess might be blocking.