Revert "fix alt-backspace"

This reverts commit 2d495f0b59affce0124beafcab15742a5a9718d3.

With this, the combination won't work even for bash.
add miniview feature to terminology.

Pressing ctrl+shift+f toggles miniview on the side of each terminal/split/tab
miniview: cleanup
add miniview_init/shutdown
add termio_pty_get()
miniview: use an image ftm
miniview: fill the image from backlog
miniview: have ctrl-shift-h toggle the miniview
miniview: also draw current screen