Bump version numbers

Replace all '1.1.0' with '1.1.1' using the following command:

    find source* -type f \
        -exec grep -q 1.1.0 {} \; \
	-exec sed -i 's 1.1.0 1.1.1 g' {} +

This also sidesteps ceylon/ceylon-spec#1147.
Update for ceylon/ceylon-spec#74
Update for ceylon/ceylon-spec#1119

Closes #70.
Add tests for #70
Fix type system Turing machine

It seems the typechecker has gotten smarter. Given code like

    interface State_Start_T {}
    abstract class Input_x_T() of input_x_T {}
    object input_x_T extends Input_x_T() {}

it now determines that the intersection

    State_Start_T & Input_x_T

is Nothing, which it previously didn’t. Therefore, we have to remove the
case types from the Input classes in the type system Turing machine.
Merge branch 'update'

Due to several typechecker changes, ceylon.ast didn’t even build
anymore. The commits in this bubble fix that.

I’m creating a “merge bubble” since I generally want all commits
directly on master (reachable from master via first parent) to be “okay”
(build + tests succeed), and the first of these commits aren’t okay.