Fix JFile to normalize whitespace when loading JSON from disk

JString::operator=(ZString) already stripped whitespace between JSON
structural tokens before parsing, but JFile constructed via MFile file-
loading bypassed that path entirely, so any pretty-printed/hand-edited
JSON file silently failed every locate()/exists()/get*() call. Widen
removeWhitespace() to protected and call it from JFile constructor.

JString.h

@@ -193,9 +193,22 @@ namespace coreutils {
 
       virtual void changed(ZString key, ZString value);
 
-    private:
+    protected:
+
+      ///
+      /// Strips whitespace between JSON structural tokens (indentation,
+      /// newlines, spaces after ':'/',') - the parser expects compact JSON
+      /// internally. operator=(ZString) already calls this for in-memory
+      /// assignment; JFile's constructor also calls it after loading a
+      /// file's raw bytes, which otherwise bypasses this entirely (see
+      /// JFile.cpp). Protected rather than private specifically so JFile
+      /// can reach it.
+      ///
+
       void removeWhitespace();
 
+    private:
+
       ///
       /// Structural helpers used internally by locate()/set() to correctly skip
       /// past a value of any JSON type without being confused by JSON-structural