44: generates previousFailure in the Java code

Change-Id: Ib1dbc7e3a5211f35537992be3cf406dac35d0088
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: consider previousFailure in the type computation

Change-Id: Ie936c62ba320b3899447db3adc42c4addc8b1594
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: other tests for previousFailure

Change-Id: Ida38f77acf97b67455484bf9f70611c0fd3ee3c3
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: custom resource description strategy removed

Change-Id: I9c65dbd4142ac92e1f2c57fc5f6b1cc29a44bedc
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: error message for var decl with name previousFailure

Change-Id: Ia102d2cb4fb9f1ccda849719b5f6d8af3ce08c6a
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: name "previousFailure" is a constant in XsemanticsConstants

To avoid a useless cycle between generator and typesystem packages

Change-Id: I096a80b897e59e3adf9ba269b91b88fc092102e1
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: test executing use of previousFailure

Change-Id: I105a2edd9abe3260316185ba5595cc97a14bc438
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: incremented version and regenerated example code 

Change-Id: I88a354d21ca30520958c44916200a5b751bbe52c
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44
44: removed unused method

Change-Id: I316f43a94a13103b4e313d85c77e8bc44853dd2a
Task-Url: https://github.com/LorenzoBettini/xsemantics/issues/issue/44