- Adds traits for Matrix / Vector
- Adds basic implementation vor Matrix / Vector
- Adds basic test for the implementation
- Adds dependency to spire in emma-common

- 'element' method to aggregate over all elements in a matrix (no
  order guarantees)
- refactored 'fold' method signatur in vector to match 'element' method
- Adds plus (union) method to matrix/vector
- Minor visibility changes
- Generifies Tests to work with matrix/vector trait
- Removes * apply method from vector
- Adds hashcode and equals to Matrix/Vector
- Fix: rowVector argument was not propagated

- Changes to scala-style to allow matrix/vector operations like *,-,%*%
- Switch to Javadoc style to avoid warings from scala-style.

Allows user to write vector/matrix operations with scala primitives
as first operand, e.g. 1.0 * Matrix

- Removes methods rows() and cols() as we can not overload methods based
  on the return type, but we would either a matrix or vector based on
the user defined function. DataBag as return type would enable this
behaviour, but we would loose the indexes.
- Explicit methods for application and aggregation for rows/cols
- MatrixTest now covers all public methods

- Vector: indexed fold
- Matrix: indexed rows & columns traversal