[Maven] Set compliance level to the XtendBatchCompiler explicitly and take ${maven.compiler.target} into account. 1.5 stays as default.
see https://bugs.eclipse.org/bugs/show_bug.cgi?id=444948
[xbase][tests] Make sure ElementIssueProvider is populated around #doGenerate

see https://bugs.eclipse.org/bugs/show_bug.cgi?id=456264

Change-Id: Iafb20bd5717fa329f218850fc10df557da41870a
Merge "[Maven] Set compliance level to the XtendBatchCompiler explicitly and take ${maven.compiler.target} into account. 1.5 stays as default. see https://bugs.eclipse.org/bugs/show_bug.cgi?id=444948"
[common.types] Follow up for bug 432488

There was an ambiguity removed in the API for binary signatures.

see https://bugs.eclipse.org/bugs/show_bug.cgi?id=432488

Change-Id: Icade7874847b4c0b4137057b0bed1bb6b2ecfecf
[xbase][validation] Fixed location of error marker for invalid assignments

see bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=398302

Change-Id: I5cca18ed95f52ad71e649da2eddb9a530aad7a66