ForFail: Default failClause to null
CeylonExpressionTransformer: Improve UnspecifiedVariable

If the type is ‘null’, we use the shorter, positional arguments form.
completeCompilationUnit: Add loops (While, ForFail)

For #39.
completeCompilationUnit: Add comprehension

For #39.
completeCompilationUnit: Add spread argument

For #39.
InlineDefinitionArgument: Remove TODO comment

See #56.
completeCompilationUnit: Add named arguments

For #39.
completeCompilationUnit: Add assignment statement

For #39.
completeCompilationUnit: Add dec qualifier

For #39.
CeylonExpressionTransformer: Fix function declarations

The annotations were completely missing!
completeCompilationUnit: Add parameters

For #39.
completeCompilationUnit: Add literals

For #39.
completeCompilationUnit: Add continue

For #39.
SwitchCases: Default elseCaseClause to null
completeCompilationUnit: Add control structures

(Only the missing ones; loops and try/catch/finally were added earlier.)

For #39.
completeCompilationUnit: Add PrefixPostfixStatement

For #39.
CeylonExpressionTransformer: Improve throws

If the result is ‘null’, we use the shorter, positional arguments form.
completeCompilationUnit: Add throws

For #39.
completeCompilationUnit: Add subscripts

For #39.
completeCompilationUnit: Remove some imports

We’re not going to test a module or package compilation unit here, so we
can remove those imports.