add json-load-check helper for JSON parse errors
MANPATH needs trailing colon for system man lookup
tmux: add shortcuts for swapping adjacent panes
tmux: add shortcuts for X clipboard selection
tmux: reorganize pasting shortcuts and clean up
each: read(1) requires arguments on some systems

bin/each: 19: read: arg count
tmux: don't assume user's shell is sh(1) compatible
ignore Vim's Obsession state files (Session.vim)
fix /dev/tty errors when disk-usage run in cronjob
fix monitor orientation xrandr(1) scripts
zsh-history-substring-search no longer binds keys by default
drop 'x' alias for extracting archives; use atool