I kept seeing distracting warnings when working with these testcases,
and it's better to have good examples when writing new testcases.
I didn't touch the issue_*.slint regression tests, so those will
still be testing the old syntax.
Updated the version from 1.1 to 1.2
Renamed the header to "Slint Royalty-free Desktop, Mobile, and Web Applications License"
Added definition of "Mobile Application" and grant of right
Moved "Limitations" to 3rd section and "License Conditions - Attributions" to 2nd section
Added flexibility to choose between showing "MadeWithSlint" as a dialog/splash screen or on a public webpage
Moved the para on copyright notices to section under "Limitations"
