Merge pull request #1968 from GawainLynch/release/1.6

Put to an end the Cron interval column problem for SQLite
Allow <a href> in RSS. Fixes #1989 (for Bolt 1.6)
classes/markdownify and classes/upload should be mirrored to web root too
Sitemap in a tree with content below the list branch, to match structure of the website
Merge pull request #2122 from richardhinkamp/composer-scripthandler-fix

classes/markdownify and classes/upload should be mirrored to web root to0
Merge pull request #2123 from richardhinkamp/sitemap-tree

Sitemap in a tree