* Update gradle wrapper version
* Update spring boot version to 2.5.0-M2
* Fix wrong const of temp_dir
* Refactor error controller
* Fix startup error due to theme not found
* Refine error controller handler
* Refine multipart resolver config
* Fix ThemeRepositoryImplTest error
* Fix freemarker not found error
* chore: change jetty to undertow.
* Remove useless throws
Co-authored-by: Ryan Wang <i@ryanc.cc>
* Update gradle wrapper version to 6.6.1
* Upgrade h2 version to 1.4.197
* Make controller log more details
* Refactor FileHandler
* Fix image reader error