Added Physical Modeling in MATLAB by Alan Downey
Added more books for Microsoft Technologies

Added two links under the hood of Microsoft technologies. The link contains lots of free ebooks by MSDN member Eric Ligman over a variety of topics such as Windows Azure, Windoes Phone Development, SQL Server, Windows 8 app development, Visual Studio Guides, SharePoint, etc
Merge pull request #367 from luminousspice/ja

[ja] Add 5 books and fix escape charatcters for md
Merge pull request #368 from PrasunBannerjee/master

Added more free ebook links for Microsoft Technologies
Merge branch 'master' of github.com:lluang/free-programming-books into lluang-master

Conflicts:
	free-programming-books.md
Added more resources for Ruby and Ruby on Rails
Merge pull request #369 from iamrahulroy/patch-1

Added more resources for Ruby and Ruby on Rails
Added 'Mature Optimization'

Mature Optimization is a free ebook that was an internal performance handbook for facebook.
Merge pull request #370 from kyleboon/patch-1

Added 'Mature Optimization'