engine: exit on Ctrl-D, just like Ctrl-C

Many common CLI applications quit when stdin reaches end-of-file, as
triggered by Ctrl-D. (Examples: `python`, `bash`, `node`, `gdb`, `ed`.)
Though `jiq` is more of a TUI than a CLI, exiting with Ctrl-D still
feels familiar and intuitive to me, and was how I tried to exit `jiq`
the first time that I used it.

wchargin-branch: ctrl-d-exit
wchargin-source: b3ac9be9ce4378b8c3eb82e6d3bc3bb6403d3309

fix |sort error handling.

fixes fiatjaf#21

update screencast.

build for windows.

fix error with empty list of candidates.

Rename project name

Merge pull request fiatjaf#13 from simeji/fix-suggestion-bug

fix suggestion bug

Merge pull request fiatjaf#11 from simeji/modify-readme

Modify README.md

Merge pull request fiatjaf#9 from simeji/refactoring

0.4.0 Refactoring and new complete method

Merge pull request fiatjaf#8 from simeji/fix-currentkey

fix current key bug