Update 0.5.1 released

The release of our Milestone update performed above expectations, it's been very stable. Nonetheless, update 0.5.1 aims to further polish the newly introduced features and content.
[h2]Changelist:[/h2]
- Updated the race score screen in multiplayer to show the global leaderboard instead of the monthly.
- Updated the multiplayer menu to show the sign in as a split panel instead of a single large panel.
- Added a notice in the leaderboards menu that scores are only kept saved in multiplayer sessions.
- Added the game option to enable/disable checkpoint visual triggers.
- Fixed issue with the popup always having a small box visible behind the original popup message.
- Fixed issue with leaderboard scores in the race score screen overlapping.
- Fixed issue where the global leaderboards wouldn't show the player's best actual score over the course of the monthly leaderboards.
- Fixed pixel border masking issue in the leaderboards menu.
- Fixed multiplayer room play bar being positioned too high. It now sticks to the bottom of the screen.
- Fixed the player score panel not being cleared in multiplayer after a race when no player finished.
- Enlarged the player activity icon while in-game.
- Updated the progression bar styling to be more consistent with the general UI style.