Added Ctrl+(up/down/right/left) + Shift+(up/down/right/left)

[Bwahharharrr]

Kept the spacing format used for presentation reasons.
Added shift and ctrl + arrow key identifiers
Was unsure on the keytype numeric values so just took a guess.

[meowgorithm]

Thanks for this! Need to test a bit more before merging but so for it's working well. Some comments below.

[meowgorithm]

@Bwahharharrr Thanks for the updates! We just merged some other key stuff, so we'll rebase, sort out the conflicts, and then test accordingly.

[Bwahharharrr]

After some fighting (obviously I am a git newb), I believe I have rebased with current master then merged with the new code.

[meowgorithm]

Hey there. Just a heads up on where we are with this PR:

• Per feat: function key support #263 we're now erring on using sequences (rather than hex values) for key matching. I'm happy to make the adjustment if you'd like.
• We still need to test against urxvt, which often sends different values versus most other terminal emulators and will very likely need it's own set of values to match shift + arrow keys
• We're debating whether or not it makes sense to add a shift value to the Key struct rather than define things like both KeyUp and ShiftKeyUp. The Stringer interface would still produce values like "shift+up".

[meowgorithm]

Hey there, @Bwahharharrr. I'm not sure what happened, but I attempted to rebase master onto your branch…and when I pushed the issue closed itself. Will reopen in a new PR, as I'm also not able to re-open this one.

[meowgorithm]

Okay, re-opened as #292.