Merge branch 'google-asm-dis-oct-25' into 'master'

Google assembler disassembler catchup to oct 25

Catches up with the google branch through 2015-10-25:

* SPIR-V 0.99 Rev32
   * Core instructions, enumerants, and capabilities
* GLSL std450 extended instructions supported
* OpenCL extended instruction supported, version 1.0 Revision 1

See readme.md for missing features and known bugs, e.g.
* Fix disassembler support for non-32 bit numeric literals
* Fix: Assembler can't use extended instructions from two different imports
  in the same module
* TODO: 16-bit floating point literals

See merge request !10