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"
As outlined in #2199, there may be ways to trigger text layout code
through forward-focus before embedded fonts are registered. To fix this,
this patch replaces the init_code vector, which had the SetFocusItem
code before the font registration, with three explicit vectors for focus
setup code, code from init callbacks, and initial focus, and defines the
order in one central place in the copmiler (iter()).
Fixes#2199
