wrong location on import error message reference to undefined rule

[marcpawl]

Error message should point to location where rule was referenced in imported file, in this case Nested.g4

[mpawlowsky@vmott-mpawlowsky-seas error]$ ant
Buildfile: /home/mpawlowsky/error/build.xml

generate:
[java] error(56): error.g4:4:8: reference to undefined rule: c

BUILD FAILED
/home/mpawlowsky/error/build.xml:3: Java returned: 1

Total time: 0 seconds
[mpawlowsky@vmott-mpawlowsky-seas error]$ cat error.g4
grammar Error;
import Nested;

[mpawlowsky@vmott-mpawlowsky-seas error]$ cat Nested.g4
grammar Nested;

a:
'a' | c;

[parrt]

Adding testErrorInImportedGetsRightFilename() test.