Integrate existing, Cernunnos-based Import/Export features with the uPortal framework.

These tools allow administrators to export, manipulate, and import entities in the portal as a collection of succinct, domain-friendly XML documents. They offer many compelling advantages:
  - Primarily, they make uPortal data significantly more accessible to humans
  - They make it easy to migrate entities from one environment to another -- 'QA' to 'prod'; or 'portal.yale.edu' to 'my.wisc.edu'
  - They offer a solid foundation on which other entity-manipulation tools may be built (e.g. 'copy-user' for JHU, alm-to-dlm for Chico)

Proposed changes:
  - data.xml sheds about 80% of its bulk, and is reduced to handling data that is: (1) almost never customized; and/or (2) not handled appropriately by these tools; specifically:
    - version info
    - sequences
    - UP_PERSON_DIR (db authentication)
    - Entities that *must* have specified IDs:
      - 'system' user
      - 'Everyone' group
      - 'Portal Administrators' group
      - 'All categories' group
  - Removed entities are converted (based on an Export of what's already there) to individual XML documents in properties/db/entities/; specifically:
    - users
    - groups
    - channels
    - memberships
    - permissions
    - layouts
  - These documents get imported in the 'db' target
  - Lower-level 'import' and 'export' targets (exactly as found in import-export.xml) get added to build.xml



See http://www.ja-sig.org/wiki/display/UPC/uP2+XML+Import+Export+with+Cernunnos for a lengthy treatment of these features.