Consider inlining syntaxpain in Enigma

[supersaiyansubtlety]

Once #8 is merged, syntaxpain will only have 14 classes + the generated JavaLexer.

Since this is only used for Enigma, it would be much simpler to make changes if this were part of Enigma.

Considerations:

• maintain original license headers and follow Apache 2.0
• how to include:
  • includeBuild
  • sub-project of :enigma-swing
  • package in :enigma-swing
• the org.xbib.gradle.plugin.jflex plugin that generates JavaLexer may be a bit wonky; we'll have to make sure it doesn't break anything

[ix0rai]

i support this change! given that no one but the owner of the original lib has commented on my 2-year-old issue that caused our fork, https://codeberg.org/sciss/SyntaxPane/issues/38, i don't think we're likely to get any additional users for this version. i would prefer to put it in a sub-project instead of a package.