cleaner macros
fix off-by-one error in window size ajustment
add E_AGAIN errno test
get ajusted window size before placing buttons
check for E_AGAIN; properly stop polling finished descriptors; close out fd only once; discard too large error output
* loadsave.cc, kern.cc: clear tmp R/O flag in EmptyText.
* user.cc, loadsave.cc, kern.cc, edit.h: use symbolic View constants.