Frame#set()/ use rjust() for filling '0';
fdb//response@padding is added to be able to specify the padding char for response frame;
Frame#set()/ takes @sel[padding];
correct command name (lib* don't need extention);
debug:Shell#shell()/ split empty line makes empty Array -> no processing;
     gives [""] instead of [] to exe() in shell;
debug: Frm::Rsp@echo is moved to Field <- used in Frm::Command without Rsp extention;
fdb-ken/ get all status;