Vaadin 7 does not work on compact3 Java profile

Vaadin 7 uses Java beans introspection that is not part of the compact3 profile. It makes Vaadin unusable for embedded systems where compact3 profiles are typically used to save limited memory.

It 'd be good to make Vaadin compact3 compatible; I believe there are not much full SE dependencies in the code. For java beans introspection car we could fall back to reflection.