Modernize commit message tips

Summary: Ref T2222. Fully modernizes these tips. No callsites remain for the old methods.

Test Plan: `grep`

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2222

Differential Revision: https://secure.phabricator.com/D8457

src/applications/differential/customfield/DifferentialBranchField.php

@@ -42,4 +42,13 @@ final class DifferentialBranchField
     }
   }
 
+  public function getProTips() {
+    return array(
+      pht(
+        'In Git and Mercurial, use a branch like "T123" to automatically '.
+        'associate changes with the corresponding task.'),
+    );
+  }
+
+
 }

src/applications/differential/field/specification/DifferentialBranchFieldSpecification.php

@@ -43,10 +43,4 @@ final class DifferentialBranchFieldSpecification
     return null;
   }
 
-  public function getCommitMessageTips() {
-    return array(
-      'Name branch "T123" to attach the diff to a task.',
-    );
-  }
-
 }

src/applications/differential/field/specification/DifferentialDependsOnFieldSpecification.php

@@ -47,11 +47,4 @@ final class DifferentialDependsOnFieldSpecification
     return 'phabricator:depends-on';
   }
 
-  public function getCommitMessageTips() {
-    return array(
-      'Use "Depends on D123" in your summary to mark '.
-      'a dependency between revisions.'
-      );
-  }
-
 }

src/applications/differential/field/specification/DifferentialFieldSpecification.php

@@ -643,9 +643,6 @@ abstract class DifferentialFieldSpecification {
     return;
   }
 
-  public function getCommitMessageTips() {
-      return array();
-  }
 
 
 /* -(  Loading Additional Data  )-------------------------------------------- */