Merge branch 'JK/expressions' into 'develop'

Fixed expression templates

Brief summary:

- fixed `DistributedExpressionTemplates`
- many fixes and simplifications in `ExpressionTemplates` and `StaticExpressionTemplates`
- extended tests (unified for `VectorExpressions`, `VectorViewExpressions`, `StaticVectorExpressions`, `DistributedVectorExpressions`, `DistributedVectorViewExpressions`)
- functions `maxNorm`, `l1Norm` and `l2Norm` - convenient aliases for `max(abs(...))`, `lpNorm(..., 1)` and `lpNorm(..., 2)`
- a `cast` function which makes something like this possible:
  `float s = TNL::sum(cast<float>(vector))`, where vector elements may be `int`, `double`, etc.
- fixed result types in expression templates and vertical operations
- removed `addVector`, `addVectors`, `addElement`, `scalarProduct` and `sum` methods from all vector types


See merge request !36