minimize error messages
fix #777
fix #781 spec refinement of dynamic members
more tolerant parsing of type alias syntax and error code
more tolerant parsing of = where => expected
Unit: renamed metamodel packages for ceylon/ceylon.language#291
unused import
minimize error messages for not-visible Java types
make typechecker accept "case (-1)" for #785
bless #785 in the spec
fix tests broken by changes to c.l
fix disjointness checking for negative integer cases #785
tests for switch for #785
fix #787