ALF-16381: Incorrect mimetype detection returns text/html mimetype for .eml files, not Email

- Added simple test file which demonstrates the issue
   - Added unit test


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@44821 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/content/MimetypeMapContentTest.java

@@ -115,7 +115,13 @@ public class MimetypeMapContentTest extends TestCase
         assertEquals(
               "application/msword", 
               mimetypeService.guessMimetype("something.doc", truncReader)
-      );
+        );
+        
+        // Lotus notes EML files (ALF-16381 / TIKA-1042)
+        assertEquals(
+              "message/rfc822", 
+              mimetypeService.guessMimetype("something.eml", openQuickTestFile("quickLotus.eml"))
+        );
     }
     
     private ContentReader openQuickTestFile(String filename)