Add all example problems from scikits.bvp_solver

[davidrpugh]

Good idea to incorporate non-economic examples. Start by implementing all of the examples from the scikits.bvp_solver docs:

• [x] Example 1: A simple heat-exchanger
• [ ] Example 2: Electro-magnetic self interaction theory
• [ ] Example 3: lubrication theory
• [ ] Example 4: MATLAB example
• [ ] Example 5: Shock-wave nozzle
• [ ] Example 6
• [ ] Example 7