Sorting Flex section & minimal markdown fix
[en] Sorting Force section
[en] Sorting Forth section
[en] Sorting iOS section
Add 沉浸式学 Git http://igit.linuxtoy.org/index.html
Merge pull request #942 from viztor/patch-1

Add 沉浸式学 Git http://igit.linuxtoy.org/index.html
Add Node.js Succinctly book.
Merge pull request #943 from levibostian/nodejs

Add Node.js Succinctly book.
[en] Sorting J section
Merge pull request #944 from esparta/master

[en] Sorting some sections on english books
[es] Added Database book
25,000 stars
Merge remote-tracking branch 'upstream/master'
add think python

think pythonとはAllen Downey氏が書いているthinkシリーズの１つである．
他のThinkシリーズは[こちら](http://greenteapress.com/)からご覧になれます．
Merge branch 'master' of https://github.com/vhf/free-programming-books
Merge pull request #946 from SamuraiT/master

add thnk python
Move Awk book from Unix section to Awk section.
Awk book -> Awk section (from Unix)

Move Awk book from Unix section to Awk section and remove typo extra line.
Merge pull request #951 from hoganlong/master

Move Awk book from Unix section to Awk section.
25,000 stars