Miscellaneous bug fixes:
- Prevent parsing links in code blocks.
- Fix SnowFlat comment vote buttons.
- Improve compact number display.
- Improve delete cache performance.
- Prevent use of
<style>tag (PR #740 from @alacn1). - Remove database entries where deleted user was favorited (PR #754 from @jairlopez).
- Fix database overflow issue with many repeated words (PR #758 from @pupi1985).
- Fix mismatch between Q2A and PHPMailer email validation (PR #773 from @pupi1985).
- Fix some PHP notices on PHP 7.4.
- Add 404 response for empty tag page.