Rearrange Lapack to be like BLAS. Implement cholesky decomposition

Responded to PR comments

modified travis file

Changed input and output types

added back needed types by cgo

Fixed perl script so it compiles

Changes to genLapack to allow compilation

Reinstate test-coverage.sh

lapack64/lapack64.go

@@ -0,0 +1,49 @@
+// Copyright ©2015 The gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package lapack64 provides a set of convenient wrapper functions for LAPACK
+// calls, as specified in the netlib standard (www.netlib.org).
+//
+// The native Go routines are used by default, and the Use function can be used
+// to set an alternate implementation.
+//
+// If the type of matrix (General, Symmetric, etc.) is known and fixed, it is
+// used in the wrapper signature. In many cases, however, the type of the matrix
+// changes during the call to the routine, for example the matrix is symmetric on
+// entry and is triangular on exit. In these cases the correct types should be checked
+// in the documentation.
+//
+// The full set of Lapack functions is very large, and it is not clear that a
+// full implementation is desirable, let alone feasible. Please open up an issue
+// if there is a specific function you need and/or are willing to implement.
+package lapack64
+
+import (
+	"github.com/gonum/blas"
+	"github.com/gonum/blas/blas64"
+	"github.com/gonum/lapack"
+	"github.com/gonum/lapack/native"
+)
+
+var lapack64 lapack.Float64 = native.Implementation{}
+
+// Use sets the LAPACK float64 implementation to be used by subsequent BLAS calls.
+// The default implementation is native.Implementation.
+func Use(l lapack.Float64) {
+	lapack64 = l
+}
+
+// Potrf computes the cholesky factorization of a.
+//  A = U^T * U if ul == blas.Upper
+//  A = L * L^T if ul == blas.Lower
+// The underlying data between the input matrix and output matrix is shared.
+func Potrf(a blas64.Symmetric) (t blas64.Triangular, ok bool) {
+	ok = lapack64.Dpotrf(a.Uplo, a.N, a.Data, a.Stride)
+	t.Uplo = a.Uplo
+	t.N = a.N
+	t.Data = a.Data
+	t.Stride = a.Stride
+	t.Diag = blas.NonUnit
+	return
+}