[Bug-apl] Parser simplification

[Juergen Sauermann]

Hi,

I have simplified the GNU APL parser a little.

For / ⌿ \ and ⍀ it is no longer needed to put names left of eg. / in () in order to have
them parsed as functions compress/expand instead of operators reduce/scan. And some constructs
like /¨ do not cause a DOMAIN ERROR as IBM APL2 does.

      (1 1) (1 0) /¨ 'ab' 'cd'
 ab c

SVN 763.

/// Jürgen