Forthcoming fixes

Changes for upcoming version 7.6.7.

I got out of the habit of writing down all the changes made; let me try to get back into the habit. -JR

Larger changes:

1. Added a new component to the interface to expand discrete variables into categorical indicator columns.
2. Fisher combined p-values were added to the Markov checker.
3. Updated all matrix operations to the EJML library because of the improved performance it gives.
4. Removed all other matrix libraries by translating or removing old code that used them.
5. Removed the deprecated MGM algorithm. Anyone wishing to use it will need to use version 7.6.6, the last version containing it.

Small fixes

1. Added option to do sampling without replacement to the bootstrap editor in the interface.
2. Updated the calculation of the median of an array.