Sugar ops unit tests

[romainfrancois]

Sugar ops unit tests on +, -, ... need double, fail with int

[coatless]

This issue has been addressed in /inst/unitTests/runit.sugar.R for vectors (See commit 48ec3a6) and /inst/unitTests/cpp/Matrix.cpp for matrices (See PR #406)

Notes: The vector operations allow for vector on vector and vector on constant. The matrix operations only allow for matrix on constant (element-wise) manipulation.

Possible feature: Matrix Multiplication (perhaps use the % operator for element-wise manipulation similar to armadillo?) and Matrix to Matrix Addition.

Please close. (Tagging #506)