Fix built-in function linum-schedule

Because scrolling is slow when linum mode is enabled, delay updating display it.
Fix issue that defadviced el-get-growl is disabled by el-get sync

I reverted commit c4133a9abbd95cb419a867a504c91a45c8eec42e "Wrap el-get-growl in terminal-notifier-notify to use Mac OS X 10.8 Notification Center with el-get" before fixing this issue.