Replace unmaintained Dwoo templating engine

[Rebecca Blundell]

The Dwoo templating engine, which we use to process all our Smarty templates is no longer maintained. The website has been taken down and the Github project is archived: https://github.com/dwoo-project/dwoo

This may start to cause problems for us as PHP moves on and Dwoo does not keep up with the new code. Currently it has been unmaintained since 2018. It looks like Dwoo was developed to make Smarty faster, but perhaps it is no longer faster. Smarty is at least patched for the latest PHP versions.

We need to investigate what to do next in order to not be relying on an unmaintained library for all our templating. We can probably patch it ourselves for a limited time, but will need to move on from Dwoo.

[Kristina Hoeppner (kris-hoeppner)]

This was discussed in the 81st developer meeting. Minutes are at https://wiki.mahara.org/wiki/Developer_Area/Developer_Meetings/81

Earliest that this can be looked into: After the 20.10 release.

[Doris Tam (doristam)]

Quoted from the 81st developer meeting "It was mentioned that changing to Smarty templates would be the easiest as Dwoo was a fork of Smarty back in the past and so much of the template content would not change."

Switching to Smarty sounds like the next step

[Doris Tam (doristam)]

Fun fact, the template language for PHP called Twig is already being used in Mahara for behat-html-formatter

> ./composer.phar why twig/twig
emuse/behat-html-formatter v0.1.0 requires twig/twig (~1.0)

[Mahara Bot (dev-mahara)]

Patch for "main" branch: https://reviews.mahara.org/12286