Merge branch 'expression-templates' of mmg-gitlab.fjfi.cvut.cz:mmg/tnl-dev into expression-templates

Matrices

See merge request !16

Moved getNonZeroRowLengthCudaKernal to SparseRow_impl.h and indentified errors in SparseRow_impl.h . Commiting for backup purposes.

Deleted useless code, reformatted present code. Still have issues with getNonZeroRowLength. getRow() throws SegFault and so does resultCuda. Commiting for backup purposes.

a row. Commiting for backup purposes.

Re-added back all tests, including CPU and GPU. Re-added multi row lengths. Commiting for backup purposes.

Changed implementation of getting Non-Zero elements. Added problem to comments. Commiting for backup purposes.

Added elements into set compressed row lengths to test getNonZeroElements correctly. Set the row length to the same value, for easier testing. Commiting for backup purposes.

Reformatted getNonZeroRowLength to pass on the device Type in string and thus enable the lambda in SparseRow_impl.h

Tried using std::vector to avoid having to implement DeviceType into SparseRow. Commiting for backup purposes.

Moved test implementations to _impl.h. Reformatted code. Changed long commented out sections to fake ifdef.