Before, we were using both __file__ as well as sys.argv[0] to determine the base directory
for Scyther, and we were not taking symlinks into account.
By using the inspect module, we can consistently pick the current frame and derive
the file from that, then use realpath to strip symlinks.
To do: We still need better error handling.
- File exists: overwrite?
- Write failed popup.
- Check for empty file at the end (what if dot does not support this particular
output format?)
