other tests for scope provider and content assist

Change-Id: I3f8ad6d06e591410ce4ac51c83ed8eed29ff4415
removed some useless code in TupleType

Change-Id: I3a9b1d376d6755248acae7aa5ba74be9e227a731
task 15: check that auxiliary descriptions have at least one parameter 

https://github.com/LorenzoBettini/xsemantics/issues/issue/15

Fixes #15

Change-Id: If020a2ea6a23ca1ec559eaab2e0c48ea2ce88a77
suite for ui tests

Change-Id: I8e22d88fa49173f647db6320c560b8a8aa2f2509
test that editor contents modified invalidates model

This makes sure that Rule.getJudgment (and
XsemanticsUtils.getJudgmentDescription) is recomputed when the editor
contents are modified

Change-Id: I5adb0bb138517be8540b85fb2d0701282b340129