Log Message:
devel/smake: Update to 1.4

Changelog from AN-2021-04-21:
- smake: We now support the idiosyncratic way, GNU make implements ::=
  that results in unpredictable behavior with larger makefiles since ::=
  creates a different macro type that causes the += operator to behave
  different from the usual way introduced in January 1986 by SunPro Make.
  += does not expand the right hand side before appending to an existing
  make macro since it has been introduced in January 1986.

  += now expands the right hand side before appending to an existing
  ::= typed macro. Such a macro is created if the first assignment
  to that macro is done via ::=.

  Using such a make macro does not expand such macros at use time.
  This includes expansions to the left side and the right side of
  a colon (:) dependency list and expansions for rule commands.

- smake: The new operators :::= and +:= have been introduced in
  order to add an orthogonal (and thus better) counterpart to the
  GNU make ::= feature that has become part of the upcoming POSIX
  ISSUE 8.

  We will propose this as a new POSIX feature soon. In special since
  it has been implemented in smake and SunPro Make, see below.

  :::= assigns a normal make macro after expanding the right hand side

  +:=  appends to any maro type after expanding the right hand side

  This permits predictable behavior for larger or structured makefile
  systems (based on the "include" statement), where it is not possible
  to know easily whether a mace macro has been created with a
  NAME=value assignment or with a NAME:=value assignment.

  Note that the official method in make since 45 years (since make
  exists) to prohibit macro expansion is not to use a ::= type macro
  but rather to use two '$' signs in the related value of the macro.

- smake: The man page now mentions the new features

- smake: The option -j maxjobs is now supported, but ignored.

  This makes smake compatible to the upcoming POSIX ISSUE 8

- smake: added a new function ungetch().

- smake: version bumped to 1.4