Use piglit_vertex to properly interface with piglit_draw_rect()

Also, use piglit_link_simple_program(). It ensures that
piglit_vertex gets assigned to the proper attribute slot.
This patch fixes these tests currently failing on mesa.

V2: Use piglit_build_simple_program().
    Also, make similar changes to builtin-sample_id and
    builtin-sample-mask tests.

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Add variable color_format to configure non-multisample fbo
Use integer texture to simplify the test

Also, move non-multisample color buffer test case inside shader program.
Add testing for fbo with renderbuffer attachment
Rename Fbo to piglit_fbo and FboConfig to piglit_fbo_config

These name changes follow the naming convention used in other
shared piglit variables, functions and classes.

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Rename shared test pattern classes and functions

Name changes in this patch follows the naming convention used in other
shared piglit variables, functions and classes.
Changes:
ManifestProgram to piglit_manifest_program
ManifestStencil to piglit_manifest_stencil
ManifestDepth to piglit_manifest_depth

TestPattern to piglit_test_pattern
Points to piglit_points
Lines to piglit_lines
Triangles to piglit_triangles
InterpolationTestPattern to piglit_interpolation_test_pattern

Sunburst to piglit_sunburst
StencilSunburst to piglit_stencil_sunburst
DepthSunburst to piglit_depth_sunburst
ColorGradientSunburst to piglit_color_gradient_sunburst

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>