I'm not sure why you would want this: it wouldn't seem useful, since those application-specific commands will probably only work as intended within their own applications. And you will mess up your global actions too: you will have several actions that are triggered by the same gesture, which will have unpredictable results; I believe only the second one from the top will then be executed, or something like that.
But, if you need it for whatever reason, here's how I would do it.
1. Export all actions (not gestures).
2. Open the exported file in a text editor.
3. Remove all the lines that describe the applications (except the "Global" ones). They look like this:
<APP name="Mozilla">
class=MozillaUIWindowClass
class=MozillaWindowClass
exec=firefox.exe
4. Also delete all
</APP>
, except a single one at the end of all the actions.
5. Save and import your new file.