* Bump API patch number and header version number to 51 for this update.
Github Issues:
* Add Valid Usage statement to flink:vkCmdResolveImage to require that
source and destination image formats match (public issue 492).
* Specify that a code:char* parameter must: be a valid null-terminated
string in the <<fundamentals-implicit-validity, implicit valid usage>>
section (public issue 494).
* Removed unnecessary VU for slink:VkPhysicalDeviceFeatures which is
covered by ename:VK_ERROR_FEATURE_NOT_PRESENT already (public issue
496).
* Clarify valid usage of pname:pQueueFamilyIndices in
slink:VkBufferCreateInfo, slink:VkImageCreateInfo, and
slink:VkSwapchainCreateInfoKHR (public issue 501).
* Document that dependencies of enabled extensions must also be enabled in
the <<extended-functionality-extensions-dependencies, Extension
Dependencies>> section (public issue 507).
Internal Issues:
* Change slink:VkMappedMemoryRange valid usage to allow pname:offset +
pname:size == size of the allocation. Also, if ename:VK_WHOLE_SIZE is
used, require the end of the mapping to be aligned to a multiple of
pname:nonCoherentAtomSize (internal issue 611).
* Add issue to `VK_KHR_win32_surface` about reusing window objects from a
different graphics API or Vulkan ICD (internal issue 639).
* Require locations on user in/out in `GL_KHR_vulkan_glsl` (internal issue
783).
* Added version info to the json validation output, and updated the schema
to match (internal issue 838).
* Restructure enumerated type descriptions separately from the command or
structure they are used in, allowing better reference page generation
(internal issue 841).
* Re-sort extension appendices to be in alphabetical order within each
author ID section.
* Fix enum naming and clarify behavior for
`VK_NVX_device_generated_commands` extension.
New Extensions: