Delete Sketch.prepare()

The only remaining thing that the method did was call `ensureExistence()`.
However, a call the `prepare()` was always followed by a call to
`build()`, which already calls `ensureExistence()`, so `prepare()`
didn't have any remaining value.

Author: matthijskooijman

app/src/processing/app/Editor.java

@@ -1771,7 +1771,6 @@ public BuildHandler(boolean verbose, boolean saveHex) {
     public void run() {
       try {
         removeAllLineHighlights();
-        sketch.prepare();
         sketch.build(verbose, saveHex);
         statusNotice(tr("Done compiling."));
       } catch (PreferencesMapException e) {

app/src/processing/app/Sketch.java

@@ -873,15 +873,6 @@ private void importLibrary(File jarPath) throws IOException {
    */
   //protected String compile() throws RunnerException {
 
-  /**
-   * When running from the editor, take care of preparations before running
-   * the build.
-   */
-  public void prepare() throws IOException {
-    // make sure the user didn't hide the sketch folder
-    ensureExistence();
-  }
-
   /**
    * Run the build inside the temporary build folder.
    * @return null if compilation failed, main class name if not
@@ -949,8 +940,6 @@ protected boolean exportApplet(boolean usingProgrammer) throws Exception {
   private boolean exportApplet(String appletPath, boolean usingProgrammer)
     throws Exception {
 
-    prepare();
-
     // build the sketch
     editor.status.progressNotice(tr("Compiling sketch..."));
     String foundName = build(appletPath, false, false);