Refactoring, small improvements, and cleaning notation of IsotonicRegression
DOC more complete coverage of API linking in examples

Previously ignored non-plot files.

Avoids some link over/undergeneration
TST add test for name identification in RST generation
TST avoid nose running setup() in gen_rst.py
TST add sphinxext to testing
Changing docs from "vector" to "1d array"
TST remove dependencies for testing sphinxext
Added Windows Powershell download script
Reverting array X to vector x rename
Docstring addition and x->X
Incorporating @ogrisel's comments for simplification
More simplifications
Fixing simplification for clip
Adding test coverage for weight deprecation in IsotonicRegression and isotonic_regression
Improving exception and warning coverage
Merge pull request #3250 from mjbommar/isotonic-refactor-2

[MRG+1] Refactor and clean IsotonicRegression
ignificant refactoring, will now automatically install Python, pip, and nose. Numpy and Scipy still require manual intervention
Fixed bug with append string getting double "_py_py"
WIP: releasing the GIL in the inner loop of coordinate descent
Replaced numpy calls with blas in dual_gap