logic error introduced in df2d3cd25 ok stsp@

Fixes the following error during gotadmin pack -a: gotadmin: raw object has unexpected size

ok jamsek

ok op, jamsek

Add the TAB instruction to the test harness, and a test case for the previous commit: scroll down the log from the diff view with the J keymap when on the last loaded commit. ok stsp@

We call resize_log_view() when toggling 'F'ullscreen from the log view, but forgot to do this when toggling fullscreen from a child view if its parent is the log view. This fixes a bug that prevents scrolling down the log view from the diff view with the J keymap if already on the last loaded commit. Regress test in the following commit. ok stsp@

Part of a wider change.

Remove some system headers which are needed to be found portably.

On i386 view_split_begin_y() computed a value slightly different than on other arches, breaking the regress. Casting HSPLIT_SCALE as float unbreaks it. Diff from jamsek, committing on his behalf. Thanks!

we can't open arbitrary files after unveil(), and that's a feature! So, open it early and truncate it before use just in case screendump() ends up being called more than once. ok/tweak stsp, ok jamsek

ok stsp, jamsek

as it might not be there (for e.g. if ran under cron). Reuse instead /dev/null since it's not expected to get input from stdin. ok jamsek

ok and README update by jamsek

ncurses(3) will use the line drawing characters from the VT100 alternate graphics character set if the terminal supports this as indicated by termcap/terminfo, otherwise it will fall back to ASCII replacement characters. ok jamsek stsp