Update to Rodin 3.7 sources

META-INF/MANIFEST.MF

build.gradle

plugin.properties

src/org/eventb/core/ast/ExtendedPredicate.java

src/org/eventb/core/ast/FormulaFactory.java

src/org/eventb/core/ast/extension/IPredicateExtension.java

src/org/eventb/core/ast/extension/IPredicateExtension2.java