Add option to use Emacs behaviour for case editing commands

[xoich]

Hello, in Emacs, but also GNU readline, bash and other shell the case editing behavior is different than used here. In Emacs when you press one of these keys inside a word, only the characters up to the end of the word are affected, so if | is the cursor, and you are in this situation foo|bar and then you press M-C in the shell you get fooBar, with noise instead you get Foobar. This is the same for the other case commands.

I think there should be a compiler option to enable classic behavior.

[xoich]

hi @jangko I can try to make the changes myself if you want. Let me know how you want to proceed, there are three options:

1. remove the current behavior and leave only Emacs' one (as I did in #29)
2. make Emacs behavior the default and keep the current one as an option
3. leave the current as default and make Emacs behavior as an option

[jangko]

I prefer the 3rd option

[xoich]

ok, I created #30 for that.