add generator to create migration for version
Use transaction when setting the version, add default version based on max(), allow custom method to be called for version
if enabled, use version to determine last audit
Merge branch 'async' into bucket

Conflicts:
	lib/auditable/auditing.rb
assert that version can be inherited from parent
when enabled, use version for diffing instead of time
Merge branch 'versions' into bucket

Conflicts:
	spec/lib/version_spec.rb
allow change_user to be set by :symbol to trigger a method or as a Proc
Merge branch 'change_user' into bucket

Conflicts:
	spec/support/models.rb
add #audit_changed_by method for accessing changed_by
Merge branch 'change_user' into bucket
Merge branch 'async' into bucket

Conflicts:
	lib/auditable/auditing.rb
	spec/support/models.rb
let the cache handle converting string to symbol
Merge branch 'async' into bucket
Merge branch 'change_user' into bucket
add attr_accessible for version
Merge branch 'versions' into bucket

Conflicts:
	lib/auditable/base.rb
Merge branch 'async' into bucket
Merge branch 'async' into bucket
Merge branch 'async' into bucket