Drop the Arch table/model

Expect content.arches to be a String, of
comma seperated arch labels

Add a String arches args to Content()
constructor.

This version doesn't do any filtering yet, so
tests that expect content to be filtered
are failing.
Add utility class for parsing and comparing arches
eradicate model.Arch/ArchCurator
add liquibase to remove Arch and ContentArch tables
update import and candlepin_api for content arches
make json.model.Content return list of arch Strings
remove getParsedArches from models
call Arch.isCompatible with correct args

use PRODUCT_ARCH_ATTR contstant for product arch
attribute name
rename Arch.isCompatable to Arch.contentForConsumer

add unit tests
checkstyle cleanup
use correct arch format for content for specs
Fix bug setting compatible arch content
fix unit test to use correct product for expected
Include arches inherited from product on contents
create content in specs by arch label
checkstyle cleanups
remove config variable stub

If we want to make this a configurable feature, we
can add it back.
Merge pull request #277 from candlepin/alikins/arch_content_2

switch from Arch table to String with comma separated list of arches