Fix, use {{> yield}} tag instead of {{yield}}.

See: https://github.com/DiscoverMeteor/Microscope/commit/chapter5-1#diff-86268a1481d515783ec8f86fe20f0fd6R9
Fix a missing command in router.js

See: https://github.com/DiscoverMeteor/Microscope/commit/chapter5-2#diff-504fd89f344be1e9c4b583f3ebd7428aR11
Fix two trivial bugs in chapter-05.
Merge pull request #28 from lijunle/patch-05

Fix some bugs in Chapter 05