Merge pull request #1 from non/topic/polynomials

Topic/polynomials
Merge pull request #2 from non/topic/polynomials

Remove .DS_Store files
Benchmark problem fixed

Implemented private lazy val _degree: Int in PolyDense and PolySparse
Fixed issue with benchmark as a result of _degree incorrect
implementation
Tidied up Polynomial companion object methods
Merge pull request #151 from jamesthompson/topic/polynomials

Polynomials Benchmark Issue Fixed