Added search path for VS 2013 built-in DXSDK
Fix vec array initialization in GLSL & HLSL (should fix some DX compiler problems)

Fixes #354
Added support for semi-sharp features along face-varying boundaries:
    - added semi-sharp tag to FVar ValueTags and applied in base FVarLevel
    - re-assess status of tagged semi-sharp values in each FVarRefinement
    - detect and apply fractional weighting in InterpolateFaceVarying()
Addng a regression shape to test face-varying boundary interpolation rules
Fixed improperly initialized ValueTags in FVarLevel.
Far::PatchTables re-factor & clean-up

- remove Descriptor iterators
- switch 'unsigned int' indices to typed Far::Index

We aren't done yet... but its a step in the right direction
Change FarStencilTables indices from 'unsigned int' to Far::Index type
Redefined face varying "boundary interpolation" to "linear interpolation":
    - redefined and documented Sdc::Options::FVarLinearInterpolation
    - included "corners only" mode not possible with Hbr
    - updated usage within Vtr::FVarLevel
Fix face-varying code in examples / tutorials to reflect changes in commit 4d84dfd7beb462976dd4ceff85dbb461f50813e5
Introduces 'single-crease patch' : implements "Efficient Evaluation of Semi-Smooth Creases in
Catmull-Clark Subdivision Surfaces", Niessner et al, Eurographics 2012.

This change includes;
-topology identification for single-crease patch during adaptive refinement.
-patch array population (similar to boundary)
-sharpness buffer generation
-glsl shader

Eval stuffs will be coming.
Fix bad uv rotations on single-crease patch
Reset default prim in glViewer code example to first in list
Merge pull request #357 from stopiccot/vs2013_dxsdk_search_path

Added search path for VS 2013 built-in DXSDK
Added proper fractional weighting for semi-sharp FVar boundaries:
    - semi-sharp edges interior to FVar regions now properly recognized
    - added clear() method to FVar tags and reworked their initialization