multiple morefiles support

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@856811 b8457f37-d9ea-0310-8a92-e5e31aec5664
workaround quirky FTP server

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@857386 b8457f37-d9ea-0310-8a92-e5e31aec5664
delete semaphore options when wiping settings

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@858096 b8457f37-d9ea-0310-8a92-e5e31aec5664
delete semaphore options when wiping settings

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@858469 b8457f37-d9ea-0310-8a92-e5e31aec5664
strategy for splitting earlier for ultra-budget hosts

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@860123 b8457f37-d9ea-0310-8a92-e5e31aec5664