merge from base, from sashan@:
> - odd condition/test in PF lexer
> (and other lexers too)
>
> This commit rectifies earlier change:
>
> in the lex... even inside quotes, a \ followed by space or tab should
> expand to space or tab, and a \ followed by newline should be ignored
> (as a line continuation). compatible with the needs of hoststated
> (which has the most strict quoted string requirements), and ifstated
> (where one commonly does line continuations in strings).
>
> OK deraadt@, OK millert@
UnifiedSplitRaw
