Bugfixes concerning built-in computation (in particular related to auxiliary functions such as "isInteger" etc.), parsing/pretty-printing, and replacing proof situations
Changed implementation of built-in "Iff": Now, arguments are never reordered
Bugfix in rewrite-rule generation: Replaced "Append" by "Join"
Changed internal representation of domain operations;
Added "Nand", "Nor", "Xor", "Xnor";
Added 'negated' predicates;
Implemented subset relations and "ae" for number domains;
Minor bugfix concerning computation with quantifiers
Minor bugfix concerning parsing of subscripted "dsN"
Added set operations for integer quotient rings;
Minor bugfix concerning equality of tuples
Parsing of chains of operations;
Computing with chains of operations ('OperatorChain')
Minor bugfixes related to:
- creating sets and tuples
- computing in proofs
- parsing chains of operations
Changed simplification of global declarations
Minor bugfix related to stripping parentheses
Merge branch 'master' of jackdaw:theorema

Conflicts:
	Theorema/Language/FormulaManipulation.m
Changed implementation of operator chains and chains of relations
Merge remote-tracking branch 'amaletzk/master'

Conflicts:
	Theorema/Language/LanguageData/English.m
	Theorema/Language/Session.m
	Theorema/Language/Syntax.m
Computation Iff bug fix, UnGroup button fixed
Button refresh global declarations: "refresh-Arrow" (unicode) instead of LightBulb
global declarations

Parsing of nested globals: switching on $parseTheoremaExpressions more
carefully, otherwise globalForall is parsed as Forall.
splitAnd moved to Computation (NOT exported anymore)
for applyGolbalDeclarations we have a private "thinnedConnect" now.
thinned Connect also splits Or.
Improved display of formula lists, tooltip for origForm
Executable form refined

Atomic formula A is treated like A=True
Executable form only generated if no dangling free variables appear in condition
Bound variables are translated into appropriate patterns
DoubleStruck number domains moved from context Knowledge to Language