Please add support for other terminals

[jarun]

I use the LXDE desktop environment. My default terminal emulator is evilvte.
I changed "gnome-terminal" to "evilvte" in newcast script and the program did record a gif. The quality is good. However, it recorded the whole desktop instead of just the terminal. I believe fetching the dimensions of the evilvte window failed.
This might be reproducible with any terminal emulator other than gnome-terminal. Can you please add support for some more terminal emulators other than gnome-terminal?