Berkeley link doesn't require signup
Add french book "Calcul mathématique avec Sage", collectif
Merge pull request #450 from ericguirbal/fr

Add french book "Calcul mathématique avec Sage", collectif
Merge pull request #448 from hiisi13/master

Algorithms - Berkeley link doesn't require signup
Add Explore Flask book (crowdfunded)
Merge pull request #451 from JIghtuse/master

Add Explore Flask book (crowdfunded)
Add a ruby on rails metaprogramming book

Added "Kestrels, Quirky Birds, and Hopeless Egocentricity" under the Ruby on Rails.
Merge pull request #452 from sbagdat/patch-1

Add a ruby on rails metaprogramming book
Added two Tcl books
Merge pull request #453 from tpoindex/patch-1

Added two Tcl books