Add support for End key

Add support for End key

    - Shift + End : Delete until end of line.
    - Control + End : Delete until end of screen.

When  the End  key is  pressed  without any  modifier is  not generated  the
correct sequence for it  (going to the end of the  screen), because the size
of the  terminal is not known,  so it is  not possible write a  sequence for
this purpouse.
---
 config.def.h |   10 ++++++++--
 st.info      |    2 ++
 2 files changed, 10 insertions(+), 2 deletions(-)