Java doc warnings

[lausdahl]

The java doc comments in the generated code has errors.

Example from Overture:

--- maven-javadoc-plugin:2.9:jar (attach-javadocs) @ ast ---

8 warnings
Javadoc Warnings
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/intf/lex/ILexLocation.java:55: warning - @return tag has no arguments.
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/intf/lex/ILexLocation.java:62: warning - @return tag has no arguments.
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/intf/lex/ILexLocation.java:69: warning - @return tag has no arguments.
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/intf/lex/ILexLocation.java:76: warning - @return tag has no arguments.
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/intf/lex/ILexLocation.java:83: warning - @return tag has no arguments.
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/intf/lex/ILexLocation.java:90: warning - @return tag has no arguments.
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/lex/LexNameToken.java:228: warning - Tag @link: reference not found: HackLexNameToken
/Users/kel/data/overture/overture-git/core/ast/src/main/java/org/overture/ast/lex/VDMToken.java:281: warning - @return tag has no arguments.