Bump Aspen version to pick up a bugfix

https://github.com/gittip/aspen-python/issues/207

This is the only difference between 0.25.1 and 0.25.2.

We need this for pjax on #1184.
using the new palette
aaaaaand added the logo
ah, save the source too!
Prune old img-github directory

I created this directory as a workaround for image hosting just before
GitHub rolled out that feature for issues. The three images in here were
for #391, and I've updated the comments there with the files hosted
properly.
Specify Twitter as preferred contact method
Bump version to 9.4.1
Bump version to 9.4.1-dev
Merge pull request #1210 from gittip/aspen-bump

Bump Aspen version to pick up a bugfix
Fix regression in account merge w/ Aspen upgrade

We do an internal redirect as part of account merge, and we didn't
update the filename of confirm.html.spt when we upgraded to Aspen 0.25
(#888).
Fix bug in account merge (#1226)

Bountysource uses 'display_name' but we, under the influence of Twitter,
were trying to access 'screen_name'. This only shows up if there is a
bountysource account in the mix when merging accounts.
Merge branch 'master' into fix-account-merge
Merge pull request #1225 from gittip/fix-account-merge

Fix regression in account merge w/ Aspen upgrade
Bump version to 9.4.2
Bump version to 9.4.2-dev
use the right brown and green in favicon and charts
Merge pull request #1228 from jeromegn/colours-fix

[Fixes #1219 #1221] Use the right brown and green in favicon and charts
Bump version to 9.4.3
Bump version to 9.4.3-dev
Merge branch 'master' into more-contrib-docs

Conflicts:
	www/assets/%version/gittip.css