Make TensorTools style indices work with xTensor interface
Add Euc and Eps tensors when xTensor is used
Regenerate EM example with master branch commit eca6928f0542a28dcfad3dbc2bb3fec69a128cd6
Make sure error messages are created when using xTensor
Remove useless info message
Remove unnecessary code
Add fixme
Remove TensorTools

It's too confusing having it around at the same time as xTensor.
Rename Group symbol as it conflicts with a similar symbol in xAct
Rename Scalar symbol as it conflicts with a similar symbol in xAct
Only use characters for indices which aren't used elsewhere
Disable SetEnhancedTimes for EM-xTensor example
Make KrancManifold and TangentKrancManifold public symbols

Otherwise, xAct tends to get a bit confused.
Add DefineDerivative function
Don't define pd symbol

It should be replaced with a better solution
Update EM example to use new xTensor interface