better operator type inference with anon types
fix npe
syntactic support for * and + instead of ... for #533
Merge branch 'defaulttypeargs' of https://github.com/ceylon/ceylon-spec into 533
render types using new syntax
fix #532
simpler more consistent impl of #532
validate that default type arg does not refer to type parameters
Merge branch 'master' of https://github.com/ceylon/ceylon-spec into 533
prevent aliases being defined recursively to fix #524
fix #530 by relaxing type constraint checking on types that appear in
is conditions (we can relax more syntactic positions later) 
error code
Merge branch 'master' of https://github.com/ceylon/ceylon-spec into 533

Conflicts:
	src/com/redhat/ceylon/compiler/typechecker/analyzer/ExpressionVisitor.java
	test/main/aliases/Aliases.ceylon
	test/main/aliases/unionintersection.ceylon
minor
don't check variance of unshared members fixes #375
check that members accessed on other instances are def initialized
correctly render +s
improve error messages
render + in tuple types
support postfix + syntax for "at least one"
fix handling of new type abbreviation syntax
fix an NPE