Adds Twitter Bootstrap's files

modified:   app.yaml
new file:   blog/assets/bootstrap/css/bootstrap-responsive.min.css
new file:   blog/assets/bootstrap/css/bootstrap.min.css
new file:   blog/assets/bootstrap/img/glyphicons-halflings-white.png
new file:   blog/assets/bootstrap/img/glyphicons-halflings.png
new file:   blog/assets/bootstrap/js/bootstrap.min.js
modified:   blog/templates/base.html
New design for the Index and Details templates

new file:   blog/assets/css/main.css
new file:   blog/assets/css/main.sass
modified:   blog/models.py
modified:   blog/templates/base.html
modified:   blog/templates/create.html
modified:   blog/templates/details.html
modified:   blog/templates/edit.html
modified:   blog/templates/index.html
modified:   blog/views.py