adds useful method removeField

bibtexbrowser-test.php

@@ -562,6 +562,14 @@ class BTBTest extends PHPUnit_Framework_TestCase {
         unlink($test_file);
     }
 
+    function test_removeField() {
+        $btb = $this->createDB();
+        $first_entry=$btb->getEntryByKey('aKey');
+        $this->assertTrue($first_entry->hasField('author'));
+        $first_entry->removeField('author');        
+        $this->assertFalse($first_entry->hasField('author'));
+    }
+    
 } // end class
 
 ?>

bibtexbrowser.php

@@ -1207,6 +1207,13 @@ class BibEntry {
     }
     return $value;
   }
+
+  /** removes a field from this bibtex entry */
+  function removeField($name) {
+    $name = strtolower($name);
+    unset($this->raw_fields[$name]);
+    unset($this->fields[$name]);  
+  }
   
   /** Sets a field of this bib entry. */
   function setField($name, $value) {