Merge changes from origin/7.1

16d17f9 Fix native scrolling regression in iOS 6 homescreen apps (#12295)
7212e02 Fix race in VaadinService.lockSession() (#12282)
2d5a107 Update "lastRequestedFirstvisible" field value right away (#10666).
325cdf9 Disable failing calendar Actions Menu Test (#12181)
8ba4117 Split UiAccess test (#12332)

Change-Id: I30e7aaacaf0ecbdc1a6dbdf956a6e48f4846de32

diff --cc server/src/com/vaadin/server/VaadinService.java
Simple merge