xlsx export as default excel export type
fixed check for outdated exports to only consider successful exports
Merge pull request #1087 from modilabs/xlsx-as-default

xlsx export as default excel export type
Merge pull request #1088 from modilabs/1086_export_caching_check_bug

fixed check for outdated exports to only consider successful exports - closes #1086
Merge branch 'master' into sms_support