docs(README): remove jquery-UI 1.11 incompatibility notice

Bower dependency limit is still there. Further discussion should continue in #214.
refactor(sortable): move connected lists cancel() test
refactor(tests): abstract connected lists dx&dy dragging
refactor(tests): move nested lists tests in separate file
test(sortable.e2e.multi.spec): make connected lists floated
chore: remove jquery-ui maximum version limitation
Merge pull request #220 from thgreasi/jqui1.11upgrade

refactor(tests): tweak tests to support jquery-ui v1.11