[xtend] Fixes bug 453498: don't generate the class comment twice when there are no imports and no package declaration

Change-Id: I595f5a3ab08616058b6ec5ec173645c8b72c778b
Signed-off-by: Miro Spönemann <miro.spoenemann@itemis.de>
[454551] Fixed link to Xtext grammar language documentation

Change-Id: Iaabba1df9d2514ef9e84347c38fe007ddfb2ae76
Signed-off-by: Miro Spönemann <miro.spoenemann@itemis.de>
Merge "[xtend] Fixes bug 453498: don't generate the class comment twice when there are no imports and no package declaration"