Fix typos in base.css file

"wekit" -> "webkit"

Fixes #105
Fix Google Maps integration

* fix CSS issue conflict with twbootstrap, where img is given
"max-width=100%"; this makes the "close button" unreachable
* clean unnecessary "poly/array" import
Use default cloudfoundry java-buildpack

Now that Java8 is the default Java version in the cloudfoundry
java-buildpack, we can now forget about our buildpack fork.

Fixes #465
Downgrade default number of instances

Part of the "heavy traffic" is now absorbed by our CDN provider, since
many requests were targeting Sagan's ATOM endpoint constantly.

Thourough tests using New Relic show that we can safely downgrade to 3
instances by default.