WIP: Caching produced type and results of is
TypeDescriptor: Fix NPE
Delete SequenceAppender and move SequenceBuilder to com.redhat.ceylon.compiler.java.language.
AbstractIterable: Use Iterable's implementation of getSequence()
Now that SequenceBuilder isn't visible to ceylon it no longer needs metadata annotations
Rewrite Iterable.sequence to not use a SequenceBuilder, but instead a helper function.
Fix #459
Fixup to SequenceBuilder
fix tests to not use SequenceBuilder
AbstractArrayIterable and subclasses: Pass around the reified element, since using the type of the array is not sufficient.
remove sequential.ceylon
merge sequential.ceylon into Sequential.ceylon
fix parameter to reifyCeylonType
rest must be a Sequential
add type parameter to suppressed exceptions array
force creation of the character sequence
work on #382
remove SequenceBuilder to fix #382
fix for some cases that hadn't come up before
Merge remote-tracking branch 'origin/sans-SequenceBuilder'

Conflicts:
	runtime/com/redhat/ceylon/compiler/java/runtime/metamodel/Metamodel.java
	runtime/com/redhat/ceylon/compiler/java/runtime/model/TypeDescriptor.java
	test/arrays.ceylon