Update free-programming-books-ko.md

removed "Algorithms" (DP+V)

Added two new titles to the Mathematics category.

Add SOS operating system link (http://sos.enix.org/fr/SOSDownload)

[ID] Update: New MongoDB link

add "Programming OpenResty" to section "OpenResty"

According to Prof. Papadimitriou, the pdf we were linking to (as well as others on the internet) are not authorized by the current copyright owner, McGraw Hill.

Added:

Basic Algebra, Digital Second Edition (Anthony W. Knapp)
Advanced Algebra, Digital Second Edition (Anthony W. Knapp)

A book about an Nginx-based web development platform called OpenResty.

Add link to free ebook for Node.js in Bahasa Indonesia

Removed Python Algorithms (PDF): Invalid Link

Removed the following link:
* [Python Algorithms](http://kysmykseka.net/koti/wizardry/Programming/Python/Apress%20-%20Python%20Algorithms%20Mastering%20Basic%20Algorithms%20in%20the%20Python%20Language.pdf) (PDF)

PowerShell Community Books

Fix some 404s