change default per page num to 15
Index.html's announcement  and  keywords, description.
Merge pull request #3 from tengcong/zyc

announcement and keywords, description.
refine keyword and description
bug fix
Merge pull request #4 from tengcong/zyc

refine keyword and description
fix meta links turbolink load 4 ever bug
add friend-site panel
add swiftgiide friendship