Basic code cleanup

Additionally fixed:

• Several missing brackets in if/else/while/foreach statemets.
• Several fixes of missing t() or with faulty formatted strings (e.g. in the hook_help)
• Refactored _php_errors_get_roles_emails(), now it uses db_placeholders() to properly cleanup the user roles in the db_query().
• Addes several missing comments at the function declarations.
• In PHP 5.3 deprecated split and join replaced by implode and explode.
• count() replaced by !empty() where possible (its more safe and less CPU intensive).

Plus fixed the following bug which will cause undesired behavior:

-  if (!count($users)) break;
-  
+  if (empty($users)) {
+    return;
+  }

(Break will do nothing since we are not inside the loop so the code will continue to execute.)

The INFO file needs cleanup as well.

PS: Just noticed that my patches in the previous comment has wrong encoding and line endings, sorry for that.

Additionally fixed:

• Constants should be in uppercase.
• Table names in DB queries should be delimeted curly brackets.

Interdiff is against #1.