Fix two small bugs in artists/showcase views.

- Fix work class height so that bottom border 
doesn't jump when images are changed.
- Fix rendering of artist name in alt text.
- Remove outdated comment and simplify how artist
name is derived.
Mobile user agent detection and views.

Preliminary testing for the following user agents,
with a few resulting style tweaks:

Chrome - Android tablet
Chrome - Android mobile
Firefox - Android tablet
Firefox - Android mobile
iPhone - iOS4
iPhone - iOS5
iPad - iOS4
iPad - iOS5
Android 2.3 Nexus S
Android 4.02 Galaxy Nexus
BlackBerry Playbook 2.1
BlackBerry 9900
BlackBerry BB10
MeeGo Nokia N9
Precompile assets.