v0.4.2

What's Changed

• Added ctx object to all system struct's constructors by @aelsabbahy in #837
• Changed: Reworded syntax error messages to be clearer by @aelsabbahy in #838
• Fix json by @aelsabbahy in #841
• Command empty strings by @aelsabbahy in #839

Full Changelog: v0.4.1...v0.4.2