Reviewed by davep.

SH-2038 PROGRESS -- Hacked the code to not render alpha using VBO's on OS X since everything renders faster using VBO's except alpha for some mysterious reason.

SH-1619 FIX
SH-1620 FIX
SH-2621 FIX

* Got lighting, shadows, and ambient occlusion working on ATI macs.
* Re-enabled ambient occlusion on ATI macs.
* Re-enabled depth of field on ATI macs.

Reviewed by Runitai Linden.

SH-2276 Fix for TDR's on GTX 460 et al -- don't use texture units above 16 (workaround for prevalent driver bug)

storm-1581: modify feature table rules to increment version only when the intent is to reset all graphics preferences

EXP-997 FIX -- Significant FPS degradation in 2.8.0 Beta on Mac equipped ATI video card

* Disabled VBO's on mac to avoid stalls in renderer
* Placed valid data into the padding between triangles in the vertex buffer to remove uninitialized craziness
* Removed invalid rendering checks causing GL errors in debug mode

Reviewed by davep

SH-2038 Disable usage of stream vbo on mac and make flexi's use stream vbo if stream vbo disabled (effectively disables usage of vertex buffers for flexible objects on mac)

Followup on mapbuffer work -- only use map buffer where map_buffer_range is available, and allow non-buffer-mapping implementation to take advantage of recorded mapped regions.

* Fixed ATI mac "lighting and shadows" related crash
* Fixed up numerous GL errors on macs related to multiple color formats,
  the use of glEnable/glDisable on textures above the texture unit count
  and old ATI-specific code that was not appropriate for Mac.
* Disabled SSAO for ATI macs due to it not working with shadows
* Ongoing work to properly get shadows and SSAO functioning on ATI macs is required.

Reviewed by davep

* Disabled SSAO on macs with 8 or less texture units.
* Slight cleanup of sunlight fragment shaders to remove unused texture units.

Reviewed by davep

* Modified mac feature table to bring it up to date with latest renderer features including deferred rendering
* Changed mac AGL pixel format to no longer allow it to revert to software rendering when shader compilation errors occur.
* Fixed up various GLSL shader compilation warnings and errors that came up as a result of the above changes.
* Changed initial conditions for the "hardware skinning" checkbox on the preferences floater so it can be modified before login on machines that support avatar vertex programs.
* Removed unused avatarAlphaF.glsl files

Reviewed by davep

SH-1387 Class0 video cards default avatar physics to high

Added appropriate featuretable entries.

SH-1387 Class0 video cards default avatar physics to high

Added appropriate featuretable entries.

Eliminated more merge artifacts.

Revert to previous behavior.  Reflections stay at "minimal".

First implementation with UI changes.

VWR-21349 Don't enable FBO by default on mac or linux when using high/ultra graphics.  Cap samples in LLMultiSampleBuffer to 4 samples to avoid using tons of memory when RenderUseFBO is set to TRUE and RenderFSAASamples is > 4.  Don't allocate multisample buffers at all when RenderUseFBO is FALSE.

VWR-21349 Don't enable FBO by default on mac or linux when using high/ultra graphics.  Cap samples in LLMultiSampleBuffer to 4 samples to avoid using tons of memory when RenderUseFBO is set to TRUE and RenderFSAASamples is > 4.  Don't allocate multisample buffers at all when RenderUseFBO is FALSE.

SH-157 Add "RenderLocalLights" to preferences and featuretable to replace old local lights on/off radio group.

SH-287 FIXED Anti-aliasing setting does not take effect until relog

Added logic to control RenderUseFBO setting based on graphics quality.  RenderUseFBO controls whether anti-aliasing is enabled.

STORM-1126 WIP Windlight Estate Settings port from 1.23: first pass at merging in windlight estate settings to viewer-dev codebase.

not built, not tested. Probably needs a bunch of fixes to be able
to be integrated.

(resubmitted by Vadim ProductEngine)

Add featuretable_xp, set default VolumeLODFactor to 0.5 for class 0 hardware, and disable impostors on Intel 965 on xp.

back-out the back-out for this branch.  yay.

Backing out this merge that I pushed (prematurely) to the wrong place.