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/edge_collapse_is_valid.h

@@ -0,0 +1,44 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2015 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#ifndef IGL_EDGE_COLLAPSE_IS_VALID_H
+#define IGL_EDGE_COLLAPSE_IS_VALID_H
+#include "igl_inline.h"
+#include <Eigen/Core>
+namespace igl
+{
+  // Assumes (V,F) is a closed manifold mesh (except for previouslly collapsed
+  // faces which should be set to: 
+  // [IGL_COLLAPSE_EDGE_NULL IGL_COLLAPSE_EDGE_NULL IGL_COLLAPSE_EDGE_NULL].
+  // Tests whether collapsing exactly two faces and exactly 3 edges from E (e
+  // and one side of each face gets collapsed to the other) will result in a
+  // mesh with the same topology.
+  //
+  // Inputs:
+  //   e  index into E of edge to try to collapse. E(e,:) = [s d] or [d s] so
+  //     that s<d, then d is collapsed to s.
+  //   F  #F by 3 list of face indices into V.
+  //   E  #E by 2 list of edge indices into V.
+  //   EMAP #F*3 list of indices into E, mapping each directed edge to unique
+  //     unique edge in E
+  //   EF  #E by 2 list of edge flaps, EF(e,0)=f means e=(i-->j) is the edge of
+  //     F(f,:) opposite the vth corner, where EI(e,0)=v. Similarly EF(e,1) "
+  //     e=(j->i)
+  //   EI  #E by 2 list of edge flap corners (see above).
+  // Returns true if edge collapse is valid
+  IGL_INLINE bool edge_collapse_is_valid(
+    const int e,
+    const Eigen::MatrixXi & F,
+    const Eigen::MatrixXi & E,
+    const Eigen::VectorXi & EMAP,
+    const Eigen::MatrixXi & EF,
+    const Eigen::MatrixXi & EI);
+}
+#ifndef IGL_STATIC_LIBRARY
+#  include "edge_collapse_is_valid.cpp"
+#endif
+#endif