Testing non-parametric window functions
Fixed format in data files
Fixed data for Hanning window (our function is equivalent to MATLAB's hann, not hanning)
Fixed triang and blackman to match standard MATLAB/Octave implementations
Remove types for method signatures from docs

Fixes #47. Also quote some arguments in the descriptions.
Use Polynomials.jl instead of Polynomial.jl
Merge pull request #48 from JuliaDSP/sjk/polynomials

WIP: Use Polynomials.jl instead of Polynomial.jl
Merge pull request #46 from jfsantos/windowtests

Testing non-parametric window functions
Clean up filter_design.jl for Polynomial

Also remove some temporary allocations, although it was unlikely filter
design would be a bottleneck
Fix filter design tests on Julia 0.2