Removed trailing whitespaces, fixed typos, and updated README.md
Make 'what' command more robust against being called with a non-function argument
Mention function dump()'s global visibility in dump command's help text
make 'what' and 'dump' commands more robust
make 'show' more robust and correctly display the current line of execution
make 'help <command>' show full command's help while omiting '|'
add readline completion