i965g: enable the driver

Add i965g to targets/egl-static and targets/pipe-loader.  Also the new target
dri-i965.
winsys/intel: new winsys for intel

This is a wrapper for libdrm_intel to allow the pipe driver to stay OS
agnostic.
i965g: new pipe driver for Intel GEN6+

This commit adds some boilerplate code.  The header files found under include/
are copied from i965.
i965g: add debug flags settable through I965_DEBUG
i965g: hook up pipe_screen param and fence functions
i965g: hook up pipe screen format functions
i965g: hook up pipe screen resource functions
i965g: add command parser

The command parser manages batch buffers and command submissions.
i965g: hook up pipe context flush function
i965g: add functions to manage shaders

This commits add shader cache, shader state, shader variant, and etc.  It does
not add the shader compiler though.
i965g: hook up pipe context state functions
i965g: hook up pipe context blit functions
i965g: hook up pipe context transfer functions
i965g: hook up pipe context query functions

None of the query types are supported yet.
i965g: add GEN6 GPE

GEN6 GPE (Graphics Processing Engine) is a low-level interface to emit 3D
commands and states.
i965g: add GEN7 GPE
i965g: add GEN6 3D pipeline

The GEN6 3D pipeline is a high-level interface to emit 3D commands and states.
It uses GEN6 GPE to do the real work.
i965g: add support for GEN7 pipeline
i965g: hook up pipe context 3D functions
i965g: add support for time/occlusion/primitive queries