nitdbg: Added function to seek a variable in the current frame

Signed-off-by: Lucas BAJOLET <r4pass@hotmail.com>
nitdbg: Added function to print the value of a variable

Signed-off-by: Lucas BAJOLET <r4pass@hotmail.com>
nitdbg: Added function to process commands
Added command print/p to print a variable

Signed-off-by: Lucas BAJOLET <r4pass@hotmail.com>