Update of the web index page
Update of the Spectra advanced example
Made mktemp compatible with OS X
Minor update of configure.sh script

- renamed the function responsible for creating temporary files
Backporting to MSVC
Minor fixup in the Spectra advanced example

- Fixed a problem with the MainFrame cleanup
Update of the configuration scripts

- Updated the configure.py script to generate a bash completion script.
- Re-generated the config/configure.bash-complete using the new functionality.
- Updated the configure-oglplus script to call configure.py.
Update of the README file
Use CMAKE_CXX_FLAGS so that linker gets the right flags.
Enable glewExperimental for MacOS X due to misreported extensions.
Open glfw window using forward compatible OpenGL 3 context.
Fix building with non-X11 OpenGL on MacOS X.