geanymacro: Use proper pointer type to retrieve a value

Apparently this even led to a crash on some situations.
geanymacro: Fix translating of actions descriptions
geanymacro: Retrieve the macro directly instead of looking it up

Since the pointer to the macro is stored in the tree anyway, retrieve
it from the tree instead of retrieving the name an looking up for this
name.
geanymacro: Fix a few memory leaks
Merge branch 'geanymacro/fixes'
Update of French translation