Many files were missing copyright, so also add a short script to add the
missing lines with the current year, and run it.
The AUTHORS file is also self-explanatory. Contributors can add
themselves there, or we can simply update it from time to time via
git-shortlog.
Since we have two scripts now, set up a directory for them.
First, unindent some of the AST code.
Second, genRandInt is unused; delete it.
Third, genRandIntn is really just mathrand.Intn. Just use it directly.
Fourth, don't use inline comments if they result in super long lines.
Implement a literal obfuscator interface,
to allow the easy addition of new encodings.
Add literal obfuscation for byte literals.
Choose a random obfuscator on literal obfuscation,
useful when multiple obfuscators are implemented.
Fixes#62