First addition of the Tutorial tab
Fix the http error after a proposal is accepted.
Upload logo: StorySense
Add StorySense logo to homepage; fix a typo in django.po
Add pycon_project/templates/_homepage_sponsor_logos.html
Merge conflicts for tutorial branch
Merged in ctchen/tutorial (pull request #1)

First addition of the Tutorial tab
Add logo: Pinkoi
Add Pinkoi logo to homepage
Add logo 'alt' text
Adjust fonts in english navbar
Move web font declaration from base.html to custom.css
Change YowuReport logo at homepage (using the wider version)
Remove redundant slash in img src URL at homepage logo area
Enlarge introduction font size in Chinese version (to better align with sponsor block)
Fix the missing translation in proposal page.

* It is because that make_safe force instantiate the lazy_object of gettext
Remove fuzzy from two translation.
Add logo: NCHC
Add '(pycon)$ python pycon_project/manage.py compilemessages' to README's "Running a web server" section
Fix invalid translation of login page