Merge branch 'ta/wait-on-aliased-commands-upon-signal' into master

When an aliased command, whose output is piped to a pager by git,
gets killed by a signal, the pager got into a funny state, which
has been corrected (again).

* ta/wait-on-aliased-commands-upon-signal:
  Wait for child on signal death for aliases to externals
  Wait for child on signal death for aliases to builtins

diff --cc git.c
Simple merge

diff --cc run-command.c
Simple merge

diff --cc run-command.h
Simple merge