Update free-programming-books-gr.md
Added HTML/CSS and Swift courses
Updated link
Added MySQL tutorial & database textbook in ja.

Added MySQL tutorial & database textbook in ja.
These books are free to share with IPA license

IPA (http://www.ipa.go.jp/index-e.html)
update Chinese resources

added new categories: vim, R
added new resources in LaTeX and Python categories
fixed a invalid link in the content
correct a misspelling
update Chinese resources

add several resources, including two new category: Erlang and Scheme
reconstruct the architecture of the .md file
Merge pull request #1083 from jinnaiyuu/patch-3

Added MySQL tutorial & database textbook in ja.
Merge pull request #1084 from sunxb10/master

update Chinese resources
Merge pull request #1 from vhf/master

update with vhf:master
update Chinese resources

added several new resources
fixed a typo
Merge pull request #1086 from sunxb10/master

Added new resources in zh.md (Chinese)
Added The GNU C Programming Tutorial
Merge pull request #1087 from bit4bit/master

Added The GNU C Programming Tutorial
Add Programación de videojueos con SDL to spanish books
Merge pull request #1088 from bit4bit/master

Add Programación de videojueos con SDL to spanish books
Merge pull request #2 from vhf/master

sync with vhf:master
Added 3 screencast on list
Merge pull request #1089 from gabrielalmir10/patch-1

Added 3 screencast on list