52999: import OLDPWD from environment if set
51722: Safety for extracting elements of $historywords
51249: use of --force-local with tar completion
50648: Use $ZCALC_HISTORY where appropriate
49792: Non-interative shell input is line buffered.
49787: test for jobs fix in 49783
49353: Fix comments in sourced file.
users/26982, subset not already integrated: use standard #include format