* Added .all() and .any() members to PartialRedux

* Bug fixes in euler angle snippet, Assign and MapBase
* Started a "quick start guide" (draft state)

doc/snippets/Tutorial_commainit_02.cpp

@@ -0,0 +1,7 @@
+int rows=5, cols=5;
+MatrixXf m(rows,cols);
+m << (Matrix3f() << 1, 2, 3, 4, 5, 6, 7, 8, 9).finished(),
+     MatrixXf::Zero(3,cols-3),
+     MatrixXf::Zero(rows-3,3),
+     MatrixXf::Identity(rows-3,cols-3);
+cout << m;