v1.18 Release

What's Changed

• Fix: use proper async pattern for Diff loading by @IsaMorphic in #17
• Fix: patches and diffs should create backup files on init by @IsaMorphic in #18
• Fix: error message should use preferred screen names by @IsaMorphic in #19
• Version bump (1.18) by @IsaMorphic in #20

Full Changelog: v1.17...v1.18