Fix several problems, discovered with "use strict" directive

Author: linev

scripts/JSRootCore.js

@@ -744,7 +744,6 @@
             var filecontent = "", u8Arr = new Uint8Array(xhr.response);
             for (var i = 0; i < u8Arr.length; ++i)
                filecontent += String.fromCharCode(u8Arr[i]);
-            delete u8Arr;
 
             return callback(filecontent);
          }

scripts/JSRootGeoBase.js

@@ -2740,7 +2740,7 @@
 
       var names = [], cnts = [], obj = null;
       for (var k=0;k<chlds.length;++k) {
-         chld = chlds[k];
+         var chld = chlds[k];
          if (!chld || !chld.fName) continue;
          if (!chld.$geo_suffix) {
             var indx = names.indexOf(chld.fName);

scripts/JSRootGeoPainter.js

@@ -2769,7 +2769,7 @@
 
          if ((center[naxis]===0) && (center[naxis]>=box.min[name]) && (center[naxis]<=box.max[name]))
            if (!this.options._axis_center || (naxis===0)) {
-               geom = new THREE.SphereBufferGeometry(text_size*0.25);
+               var geom = new THREE.SphereBufferGeometry(text_size*0.25);
                mesh = new THREE.Mesh(geom, textMaterial);
                mesh.translateX((naxis===0) ? center[0] : buf[0]);
                mesh.translateY((naxis===1) ? center[1] : buf[1]);

scripts/JSRootIOEvolution.js

@@ -716,9 +716,6 @@
 
    // ctor
    JSROOT.TDirectory = function(file, dirname, cycle) {
-      if (! (this instanceof arguments.callee) )
-         throw new Error("you must use new to instantiate this class", "JSROOT.TDirectory.ctor");
-
       this.fFile = file;
       this._typename = "TDirectory";
       this.dir_name = dirname;
@@ -790,8 +787,6 @@
 
          file.fDirectories.push(dir);
 
-         delete buf;
-
          JSROOT.CallBack(readkeys_callback, dir);
       });
    }
@@ -823,9 +818,6 @@
 
    // ctor
    JSROOT.TFile = function(url, newfile_callback) {
-      if (! (this instanceof arguments.callee) )
-         throw new Error("you must use new to instantiate this class", "JSROOT.TFile.ctor");
-
       this._typename = "TFile";
       this.fEND = 0;
       this.fFullURL = url;
@@ -1384,7 +1376,7 @@
             return JSROOT.CallBack(readkeys_callback, null);
 
          // extra check to prevent reading of corrupted data
-         if (!file.fNbytesName || this.fNbytesName > 100000) {
+         if (!file.fNbytesName || file.fNbytesName > 100000) {
             JSROOT.console("Init : cannot read directory info of file " + file.fURL);
             return JSROOT.CallBack(readkeys_callback, null);
          }
@@ -1438,13 +1430,8 @@
 
                   return JSROOT.CallBack(readkeys_callback, file);
                });
-
-               delete buf5;
-               delete buf4;
             });
-            delete buf3;
          });
-         delete buf;
       });
    };