add "e" (close-on-exec) flag to fopen(3) calls suggested by millert ok thomas_adam

implement 'got diff -c' for diffing commits with optional filtering by path Need for filtering by path sugggested by kn@ ok naddy@

indentation fixes

use gmtime_r(3) instead of localtime_r(3) to display time in UTC as intended Problem noticed by naddy due to failing regress tests at midnight, and then analyzed with additional help from millert. ok naddy

goto the right label, so we can get previous on the last page of briefs

we will never have a previous link on the summary page

fix missed commit found check

fix a glaring logic error in navigation for commits, briefs, and tags. now, we get the proper commit id from the tailq.

switch from SIMPLEQ to equivalent STAILQ macros The singly-linked tail queue macros were added to OpenBSD 6.9 and are more widely available on other systems. ok stsp

make it possible to profile gotweb; tracey had the same diff

unveil gmon.out if gotweb is being profiled ok tracey

check for close(2) error in got_repo_close() and propagate errors up ok tracey

properly render an error page instead off returning 500. bug reported by Miniontoby via irc

Fix strftime(3) short buffer checks strftime(3) returns 0 if the buffer was too short to write the complete string (including NUL) and will never return more than maxsize-1. ok stsp

make fclose(3) failure checks consistent; check 'fclose() == EOF' everywhere ok millert, naddy