mail_daemon: cleanup, 30s auto check startup delay.

* Refactored new message retrieval a bit, so that the notification strings
  aren't duplicated.
* The daemon now waits 30 seconds before doing the first mail check.

src/preferences/mail/AutoConfigView.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2007-2011, Haiku, Inc. All rights reserved.
+ * Copyright 2007-2015, Haiku, Inc. All rights reserved.
  * Copyright 2011, Clemens Zeidler <[email protected]>
  * Distributed under the terms of the MIT License.
  */
@@ -204,7 +204,6 @@ AutoConfigView::_GetSMTPAddonRef(entry_ref *ref)
 {
 	directory_which which[] = {
 		B_USER_ADDONS_DIRECTORY,
-		B_COMMON_ADDONS_DIRECTORY,
 		B_BEOS_ADDONS_DIRECTORY
 	};
 

src/preferences/mail/FilterList.cpp

@@ -35,7 +35,6 @@ FilterList::Reload()
 	std::set<BString> knownNames;
 
 	directory_which which[] = {B_USER_ADDONS_DIRECTORY,
-		B_COMMON_ADDONS_DIRECTORY,
 		B_SYSTEM_ADDONS_DIRECTORY};
 	for (size_t i = 0; i < sizeof(which) / sizeof(which[0]); i++) {
 		BPath path;