cmake: Install under separate piglit directory

Install paths updated:
* $PREFIX/share/doc => $PREFIX/share/doc/piglit
* $PREFIX/lib => $PREFIX/lib/piglit/lib
* $PREFIX/bin => $PREFIX/lib/piglit/bin
* etc...

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Dylan Baker <baker.dylan.c@gmail.com>
cmake: Add version suffix for install paths

If used, then piglit will be installed into a separate
path. For example, if '-DPIGLIT_INSTALL_VERSION=20140430'
was specified with cmake, then piglit would install
to $PREFIX/lib/piglit-20140430.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Dylan Baker <baker.dylan.c@gmail.com>
framework: move executable functions to modules

This moves piglit-run and piglit-resume main() functions to
framework.programs.run as run() and resume() respectively, and moves
piglit-summary-* to framework.programs.summary. It then creates
compatibility wrappers as piglit-*.py for the functions.

This is groundwork for a combined piglit interface. The original files
could not be imported directly since they have dash (-) in their name,
and python considered dash an illegal character for function, class, and
modules names, and python would raise an ImportError.

Signed-off-by: Dylan Baker <baker.dylan.c@gmail.com>
piglit: Add a toplevel piglit command

This uses the functions created by the last commit to create a
all-in-one piglit command. It uses argparse to parse partial commands
and provide help for those functions.

It is also capable of handling all of the black magic for setting the
python sys.path and setting the PIGLIT_SOURCE_DIR environment variable.

v2: - Allow the name of the program to not be piglit (example:
      piglit-20140101)
    - Remove unused check from cmake
    - Install piglit as piglit${PIGLIT_INSTALL_VERSION}; when this
      variable is unset piglit will be installed simply as 'piglit'

Signed-off-by: Dylan Baker <baker.dylan.c@gmail.com>