Fix build failures

- Add license headers. Also check these during pre-commit.
 - Fix javadoc issue.

config/pre-commit/config.yml

@@ -31,6 +31,13 @@ repos:
     entry: ./gradlew checkstyleMain checkstyleTest
     pass_filenames: false
     require_serial: true
+  - id: license
+    name: Check Java license headers
+    files: ".*\\.java$"
+    language: system
+    entry: ./gradlew licenseFormat
+    pass_filenames: false
+    require_serial: true
   - id: illuaminate
     name: Check Lua code
     files: ".*\\.(lua|java|md)"

src/main/java/dan200/computercraft/api/lua/GenericSource.java

@@ -1,7 +1,7 @@
 /*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 package dan200.computercraft.api.lua;
 
@@ -32,7 +32,7 @@ import javax.annotation.Nonnull;
  *
  * <pre>{@code
  * public class InventoryMethods implements GenericSource {
- *     @LuaFunction( mainThread = true )
+ *     \@LuaFunction( mainThread = true )
  *     public static int size(IItemHandler inventory) {
  *         return inventory.getSlots();
  *     }

src/main/java/dan200/computercraft/core/asm/GenericMethod.java

@@ -1,3 +1,8 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
 package dan200.computercraft.core.asm;
 
 import dan200.computercraft.ComputerCraft;