abook --devel 0.6.0-pre2

Closes #27338.
Make build_bottle an explicit installer mode
Make build_from_source an explicit installer mode
reduce the number of things that trigger ARGV.build_from_source?
explicitly pass options to installer
temporarily disable bottles
delegate top-level bottle DSL to stable spec
update tests
decouple Bottle from SoftwareSpec
bottle DSL creates BottleSpecification objects
remove hack from installer
add bottled? method to softwarespec
add new Bottle class that wraps bottlespecification
eliminate bottle_current method
re-enable bottle from formula
remove options check from install_bottle?

this is now handled by explicitly passing build options into the
installer.
wrap cellar check in a method
update brew info for generalized bottle impl
update fetch for generalized bottle impl
update bottle command for generalized bottle impl