Rename packages to make room for other workflow backends.

[danielgmyers]

• com.danielgmyers.flux.clients.swf:flux-swf-client-pom -> com.danielgmyers.flux:flux-base-pom
• com.danielgmyers.flux.clients.swf:flux-common -> com.danielgmyers.flux:flux-common
• com.danielgmyers.flux.clients.swf:flux-testutils -> com.danielgmyers.flux:flux-testutils
• com.danielgmyers.flux.clients.swf:flux -> com.danielgmyers.flux.clients.swf:flux-swf
• com.danielgmyers.flux.clients.swf:flux-spring -> com.danielgmyers.flux.clients.swf:flux-swf-spring
• com.danielgmyers.flux.clients.swf:flux-guice -> com.danielgmyers.flux.clients.swf:flux-swf-guice
• com.danielgmyers.flux.clients.swf:flux-integration-tests -> com.danielgmyers.flux.clients.swf:flux-swf-integration-tests

https://github.com/danielgmyers/flux-swf-client/issues/87