Merge pull request #451 from est77/master

Made fresnel multiplier param of SpecularBTDF texturable.
Made Material a real polymorphic class.
Small formatting fix.
Merge pull request #452 from est77/polymorphic_materials

Made Material a real polymorphic class.
small code cleanups.
added foundation::binomial().
made foundation::binomial() inline.
Update README.md
no longer ship the old blenderseed plug-in with appleseed releases.

blenderseed is now a separate project: https://github.com/appleseedhq/blenderseed
Merge branch 'master' of github.com:appleseedhq/appleseed
added profile picture for 3DVF forum.

http://www.3dvf.com/forum/
tweaked license.
appleseed.package.py 2.3.7: print system commands as they are executed.
appleseed.package.py 2.3.8: make sure Qt package files are writable before fixing them up (OS X only).
fixed sporadic crashes when exiting appleseed.studio.
merge commit
Merge pull request #456 from sriravic/curve_merge_branch

Basic curve rendering functionality
code fixes and cleanups.
fixed compilation on gcc, sped up curve unit tests, further cleaned up the code.
fixed regression in unit tests introduced in previous commit and further cleaned up the code.