Add .WAITs after beforeinstall and before afterinstall.
Remove the bogus dependency lines that someone must have added with the
vague hope they would cause the build to happen in the right order!
Since we have 'realinstall: proginstall scriptsinstall' stopping
'realinstall' running never has stopped 'proginstall' running.
Fixing this probably fixes a variety of problems, including, but not
restricted to 'install' in src/sys/arch/atari/stand/bootxx
(NB this particular file is untested due to other local changes)