Reword for shorter lines, make authorship generic

Shorter lines are a good idea: namely, with this line length, you can prefix every line of the license with a comment sequence like `// `, a patchset indicator like `+`, and a couple quote brackets like `>>` without overflowing an 80-character terminal.

For example:

```
To: Upstream
From: Submitter
Subject: Re: Add license
Glad to hear!

Upstream wrote:
> Looks great!
>
> Submitter wrote:
>> Should probably add a license.
>> This patch adds the LITL:
>>
>> @@ -1,3 +1,6 @@
>> +// Copyright <year> <copyright holders>.
>> +// This work may be used freely as long as this notice is included.
>> +// The work is provided "as is" without warranty, express or implied.
>>  int main(int argc, char **argv) {
>>    return 0;
>>  }
```