uses a TaskContext again.  Added some regression tests.

* Changed Embeddor.createWorkspace() to use a Map, rather than a Parameters,
  to supply initial workspace properties.  Initial properties can be Objects,
  rather than only Strings.  Got rid of the Object -> String convertion from
  <ant> and <antcall>.

* Generalised ExecutionFrame, so that it can represent any execution scope
  (root, workspace, project, task, inherited, etc), rather than just task scope:
  - Replaced getTaskContext() with getPropertyStore().
  - Replaced getTypeManager() with getServiceManager().

* Executor is now responsible for creating TaskContext.

* Changed DefaultExecutor to use the configurer provided by the execution frame.

* Added ExecutionContainer, a lifecycle interface which is used to supply the
  root execution frame to a service which executes tasks (directly or indirectly).

* Changed interaction between DefaultEmbeddor and workspaces.  Embeddor is now
  responsible for creating the base property store for workspaces.  ExecutionContainer
  is used to pass this to workspaces.  Parameterizable is now used to pass
  container params to workspaces (which matches how it is used with all the
  other services).


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@272302 13f79535-47bb-0310-9956-ffa450edef68