Release build 6.17-9
    - Make wait builtin command interruptible
      Resolves: #440465
    - Remove fork when tcsh processes backquotes
      Resolves: #594536
    - Don't set $REMOTEHOST on the local machine
      Resolves: #669176
    - Don't print history in verbose mode
      Resolves: #583075, #658171
    - Don't allow illegal variable names to be set
      Resolves: #436901