Remove support for package declaration in aspect files

[Jesper Öqvist]

JastAdd2 2.1.11-29-g24f55d4

JastAdd allows package declarations in aspect files, but they do not affect anything in the aspect weaving or code generation so we should be able to remove this feature.

[Jesper Öqvist]

Disable package declaration parsing

Package declarations were parsed by the aspect file parser, but did not affect anything in aspect weaving or code generation.

fixes #227 (bitbucket)

→ <<cset 48b358621ce6>>