[new compiler] Preliminary support for QQmlIncubator

Just enough to run some unit tests that use QQuickLoader, components are
created instantly.

Change-Id: I1c827aa946d3e2a60ccc220bb79572aca2ed8c96
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
[new compiler] Initial support for custom parsers

Enough to support the Connections {} element. What's missing are pre-compiled
bindings signal handlers.

Change-Id: I3ad1413fa636434d899ae8fb380249aaf40363dc
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
[new compiler] Fix assigning signal handlers

When assigning a signal handler to the fooChanged property, we need to
look up fooChanged as signal function, not as data property.

Change-Id: I4c0e4374cea8ce9596428975e45e78a0b743a6fc
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
[new compiler] Fix signal handlers for properties declared in the same object

We need to generate the property caches before we can try converting the
signal handler expressions in the AST to function declarations, as that
conversion requires looking up the signal signature / meta-data from the
property cache. This in turn requires rewriting the property cache
generator code to operate on the data structure we have before creating
the QV4::CompiledData.

Change-Id: I0d1c59d947f36171b4eb89f47a2e1ff1bc493c6f
Reviewed-by: Lars Knoll <lars.knoll@digia.com>