45: data field in ErrorInformation

Change-Id: Id57733714fa412d6773a00c18d0a282c6544740d
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/45
45: Allow to store any "data" in an error specification 

Change-Id: I1ed4e659ddf0d8bd5498d2011a7a3d20443117d7
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/45
45: tests using "data" in an error specification 

Change-Id: Iddf0e26aa864e29f39d0b259ebbc1eb13112f255
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/45
avoid duplicated code

Change-Id: I512df25be09732897febf49f944d98744071ccc0
ErrorSpecification elements in any order

Change-Id: I2ba5a06ee567432eacc3b4aa87ff299c553e0bfc
Incremented version 1.7.0

Due to the change in the runtime library ErrorInformation.getData()

Change-Id: I81a1d7ca525b5ee96ed81b260f3a1b8e836a9176
updated baseline to Xsemantics 1.6.1

Change-Id: I15506cd644a4659ff80ebc92a46b59337c3b83d1