Cycles Hair: Fixed hair shape and inclusion of multiple attributes for triangle primitives

When using triangle primitives this fix enables 'closed tip'. 

UVs and vertex colours are added when using triangle primitives for hair.

Two new preset modes have also been included to allow easy access to curves and triangle planes.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54256 954f8c5b-7b00-dc11-b283-0030488c597c