Clang-format sees the text behind `#pragma region` as code and formats it. Instead of stating the copyright and date there, it's now in the comment block right below it. The text "Copyright" is left in the `#pragma region` line, as clang-format sees it as a single identifier.
I took the opportunity to normalize the dates, and add the copyright notice to the source files where it was missing them (except for third-party and the generated resources.h file).
The two functions for opening were almost identical. The only
difference was that one was passed a string ID and the other a
raw string. The one taking the string ID now converts it to a
raw string, and then calls the other functions.
This also makes the utf8 string const and replaces some C-string
code with String::Set.