Merge branch '286-fix_regressions' into 'master'

Issue 286: fix regressions after `Extend device feature and limit validation in dEQP-VK.api.info`

This fixes few bugs introduced in new `dEQP_VK.info.image_properties` added in issue #286:

* The enum value 1<<31 is cast in test to VkDeviceSize, which is 64-bit unsigned int. According to C++
standard it is undefined wether enums are signed, or not, so the resulting value can be 0x8000000 or 0xffffffff80000000.  At least this happens on MSVC++.

* properly calculate mip pyramid size. It should be log_2(size) + 1, not log_2(size).

See merge request !445