rename the case array to wcase, as gawk can be compiled with support for

switch/case, in which event case is a reserved word, and causes errors.
Closes gh-2.

z.sh

@@ -105,14 +105,14 @@ z() {
     } else if( typ == "recent" ) {
      f = t-$3
     } else f = frecent($2, $3)
-    case[$1] = nocase[$1] = f
+    wcase[$1] = nocase[$1] = f
     for( i in a ) {
-     if( $1 !~ a[i] ) delete case[$1]
+     if( $1 !~ a[i] ) delete wcase[$1]
      if( tolower($1) !~ tolower(a[i]) ) delete nocase[$1]
     }
-    if( case[$1] > oldf ) {
+    if( wcase[$1] > oldf ) {
      cx = $1
-     oldf = case[$1]
+     oldf = wcase[$1]
     } else if( nocase[$1] > noldf ) {
      ncx = $1
      noldf = nocase[$1]
@@ -120,7 +120,7 @@ z() {
    }
    END {
     if( cx ) {
-     output(case, cx, common(case, a, 0))
+     output(wcase, cx, common(wcase, a, 0))
     } else if( ncx ) output(nocase, ncx, common(nocase, a, 1))
    }
   ' $datafile)"