Build system: ADD Rake::TaskInfo

Formal interface to task name => optional desc pairs.
Build system: use TaskInfo for SmartFileTask

Also: leave group task coallescing to Rake, it does a good job of it…
Build system: FIX duplicated groups in SmartFileTask
Build system: FIX group task assignment in SmartFileTask
Build system: clean up SmartFileTask

* use `instance_exec` for @action (assigned via `on_run` block) – much
cleaner than lambdas.
* clean up accessors, rename @base to @deps
Build system: use new SmartFileTask interface in MustacheTask
Build system: use new SmartFileTask interface in ZipTask
Build system: use new SmartFileTask interface in Rakefile

Includes SmartFileTask children, i.e. MustacheTask and ZipTask.
Build system: FIX template accessor in MustacheTask
Build system: FIX files accessor in ZipTask
Build system: ADD OS X::Bundle convenience class
Build system: REMOVE OSX::Plist path guessing

OSX::Bundle will get the path if needed.
Build system: REMOVE BundleEditorTask

Bundle functionality now resides in OSX::Bundle, and the tasks are much
better defined as enhancements than task of their own anyway…
Build system: REMOVE named build tasks dependencies

Package file tasks now correctly post pocess the egenrated bundles, so
we can shorten the dependency chain.
Build system: ADD short format to version/conversions

Because `Version` chokes on two letter prerelease codes … gah. Also add
“golden master” as a prerelease code.
Build system: clean up task list
Build system: create master change log with GitChangelogTask
Build system: conform master change log keys to tag names

`2.0.0rc1` for legacy download compatibility reasons; future release
tags must  conform to the `Version.current` code.
Build system: FIX data assigment in MustacheTask constructor
Build system: FIX verbosity of bundle post processing

We don’t have access to the task ivars…