Merge pull request #52 from Queequeg92/master

add test code for exercise 16.3; improved 16.4.
Merge pull request #54 from Queequeg92/master

fix a constructor bug
Merge pull request #55 from Queequeg92/master

A solution for exercise 16.15
Merge pull request #56 from Queequeg92/master

Add an ostream parameter
Merge pull request #57 from Queequeg92/master

type alias for brevity.
Merge pull request #58 from Queequeg92/master

A solution for exercise 17.6
fixed ex5_17.cpp
Merge pull request #59 from pezy/upstream

fixed a bug for ex5_17.cpp
Merge pull request #60 from Queequeg92/master

Template functions update and mark.
Merge pull request #3 from Mooophy/master

SYN