Merge pull request #2 from vhf/master

sync with vhf:master
Merge pull request #3 from vhf/master

sync with vhf:master
Merge pull request #4 from vhf/master

sync with vhf:master
Added Markdown & reStructuredText in -zh.md
Merge branch 'master' of https://github.com/sunxb10/free-programming-books
fixed formatting
Dart added
delete a duplicated book
add new course
Merge pull request #1102 from N19270/delete-link

delete a duplicated book
Merge pull request #1103 from N19270/add-course

add a new course
Update free-programming-books.md

Handbook of Graph Drawing and Visualization
Merge pull request #1105 from manasij7479/patch-1

Update free-programming-books.md
Fix indent issue for meteor resource
Added Vic Ramon's Ember tutorial
Merge pull request #1106 from katgironpe/master

Added Vic Ramon's Ember tutorial
Merge pull request #1101 from mhmmdd/master

Dart added
Merge pull request #1097 from sunxb10/master

Added Markdown & reStructuredText in -zh.md
the link to the free version is now dead.
links to free version are all dead