Building igl statically and moving to the dep scripts

Fixing dep build script on Windows and removing some warnings.

Use bundled igl by default.

Not building with the dependency scripts if not explicitly stated. This way, it will stay in
Fix the libigl patch to include C source files in header only mode.

src/libigl/igl/pinv.cpp

@@ -0,0 +1,35 @@
+#include "pinv.h"
+#include <limits>
+#include <cmath>
+
+template <typename DerivedA, typename DerivedX>
+void igl::pinv(
+  const Eigen::MatrixBase<DerivedA> & A,
+  typename DerivedA::Scalar tol,
+  Eigen::PlainObjectBase<DerivedX> & X)
+{
+  Eigen::JacobiSVD<DerivedA> svd(A, Eigen::ComputeFullU | Eigen::ComputeFullV );
+  typedef typename DerivedA::Scalar Scalar;
+  const Eigen::Matrix<Scalar,Eigen::Dynamic,Eigen::Dynamic> & U = svd.matrixU();
+  const Eigen::Matrix<Scalar,Eigen::Dynamic,Eigen::Dynamic> & V = svd.matrixV();
+  const Eigen::Matrix<Scalar,Eigen::Dynamic,1> & S = svd.singularValues();
+  if(tol < 0)
+  {
+    const Scalar smax = S.array().abs().maxCoeff();
+    tol = 
+      (Scalar)(std::max(A.rows(),A.cols())) *
+      (smax-std::nextafter(smax,std::numeric_limits<Scalar>::epsilon()));
+  }
+  const int rank = (S.array()>0).count();
+  X = (V.leftCols(rank).array().rowwise() * 
+      (1.0/S.head(rank).array()).transpose()).matrix()*
+    U.leftCols(rank).transpose();
+}
+
+template <typename DerivedA, typename DerivedX>
+void igl::pinv(
+  const Eigen::MatrixBase<DerivedA> & A,
+  Eigen::PlainObjectBase<DerivedX> & X)
+{
+  return pinv(A,-1,X);
+}