Vertex buffer functions in NTT

All the usual stuff (with addition of _valid).

vertex_create_buffer()​➜
vertex_create_buffer_ext(size)​➜
vertex_delete_buffer(vbuf)
vertex_valid(vbuf)​➜
vertex_begin(vbuf, vfmt)
vertex_end(vbuff)
vertex_position(vbuff,x,y)
vertex_position_3d(vbuff,x,y,z)
vertex_colour(vbuff,colour,alpha)
vertex_color(vbuff,color,alpha)
vertex_argb(vbuff,argb)
vertex_texcoord(vbuff,u,v)
vertex_normal(vbuff,nx,ny,nz)
vertex_float1(vbuff,f1)
vertex_float2(vbuff,f1,f2)
vertex_float3(vbuff,f1,f2,f3)
vertex_float4(vbuff,f1,f2,f3,f4)
vertex_ubyte4(vbuff,b1,b2,b3,b4)
vertex_submit(vbuff,prim,texture)
vertex_freeze(vbuff)
vertex_get_number(vbuff)
vertex_get_buffer_size(vbuff)
vertex_create_buffer_from_buffer(buf, format)​➜
vertex_create_buffer_from_buffer_ext(buf, format, src_offset, num_vertices)​➜
buffer_create_from_vertex_buffer(vertex_buffer, kind, alignment)​➜
buffer_create_from_vertex_buffer_ext(vertex_buffer, kind, alignment, start_vertex, num_vertices)​➜
buffer_copy_from_vertex_buffer(vertex_buffer, kind, alignment, start_vertex, num_vertices, dest_buffer, dest_offset)
vertex_format_begin()
vertex_format_end()​➜
vertex_format_delete(vfmt)
vertex_format_valid(vfmt)​➜
vertex_format_add_position()
vertex_format_add_position_3d()
vertex_format_add_colour()
vertex_format_add_color()
vertex_format_add_normal()
vertex_format_add_texcoord()
vertex_format_add_custom(type,usage)
vertex_usage_position = 1
vertex_usage_colour = 2
vertex_usage_color = 2
vertex_usage_normal = 3
vertex_usage_texcoord = 4
vertex_usage_textcoord = 4
vertex_usage_blendweight = 5
vertex_usage_blendindices = 6
vertex_usage_psize = 7
vertex_usage_tangent = 8
vertex_usage_binormal = 9
vertex_usage_fog = 12
vertex_usage_depth = 13
vertex_usage_sample = 14
vertex_type_float1 = 1
vertex_type_float2 = 2
vertex_type_float3 = 3
vertex_type_float4 = 4
vertex_type_colour = 5
vertex_type_color = 5
vertex_type_ubyte4 = 6