qt5: 5.0.1
mathgl 2.0.3 plus options

MathGL gets a major overhaul because it can do a lot more.

- Upgrade to 2.0.3
- By default enable glut, gsl, jpeg, png, pthread, pdf
- Disable python (refuses to find numpy)
- Disable octave interface (installs a tarball to ~/ocatave)
- Add a dep on jpeg to support our default image capability
- Add a dep on libharu to support our default pdf capability.
- Add a dep on cmake because it's the only builder now.
- Add an option to enable fltk widget and mglview using X11.
- Add an option to enable qt4 widget, udav, and mglview using Qt4.
- Add an option to enable wxWidgets widget
- Add an option to enable GIF support.
- Add an option to enable hdf5 support.
- Add optional deps for the above options.
- Remove a symlink in the source, ChangeLog, to fix install errors.
- Build OOS.
- Install the `mgl_example` files manually.
- Works well with superenv.

Closes #14799.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>