many small fixes and documentation improvements,
this should be alpha5.
diff --git a/doc/snippets/MatrixBase_quickInverse.cpp b/doc/snippets/MatrixBase_quickInverse.cpp
new file mode 100644
index 0000000..cf0575f
--- /dev/null
+++ b/doc/snippets/MatrixBase_quickInverse.cpp
@@ -0,0 +1,5 @@
+Matrix4d m = Matrix4d::zero();
+m.part<Eigen::Upper>().setOnes();
+cout << "Here is the matrix m:" << endl << m << endl;
+cout << "We know for sure that it is invertible." << endl;
+cout << "Here is its inverse:" << m.quickInverse() << endl;