Short Description: AccountGfxItem: preparation for supporting multiple Accts
Bug Number: n/a
Release notes (y/n): no
For Release Nums: 6.1

Modifed AccountGfxItem design from supporting a single Account to multiple
Accounts, in preparation for Account Icon Aggregation (controlled by an
Account Display Group property).

------------------
AccountGfxItem.hpp
AccountGfxItem.cpp
------------------

AccountGfxItems now maintain a SET of referenced Accounts, and conditionally
self-delete when the last remaining Account is removed.

Multiple-Account drawing is not yet implemented. However, for now, if 
the Item represents several Accounts (which would be in a single Account
Display Group), the Account Display Group name is shown instead of an 
Account Name.

The ToolTip text now shows one line of text for each of the supported
Accounts.  Also, for Accounts on AggregateObj Elements, the Element name
is shown in the ToolTip (before the Account Name, like this: element^account).

ACCOUNT_DELETED callbacks now result in the Account being removed from the
list of Accounts supported by this item. And if the Account count becomes 
zero, the AccountGfxItem self-deletes.

Removed:
  Account* _account;
  SimObj*  _simObj;
  Callback* _acctCallback;

Added:
  QList<Account*> _accountList;
  QMap<Account*,Callback*> _acctCallbackMap;
  QString  _groupName;
  bool _isAggregation; // does this item represent an Account Aggregation?

Added 'doSelfDelete' parameter to these methods:
  void prepareForDeletion (bool doSelfDelete);
  bool removeAccount (Account*, bool doSelfDelete);
  void removeAccounts (bool doSelfDelete);

Additional other methods to support multiple Accounts:
  Account* firstAccount() const;
  const QList<Account*>& accountListRef() const { return _accountList; }
  bool containsAccount (Account*) const;
  void addAccount (Account*);

------------------
AcctRowGfxItem.hpp
AcctRowGfxItem.cpp
------------------

This class now keeps track of AccountGfxItem children directly, rather than
maintaining a list of Accounts, and relating those Accounts individually 
with an AccountGfxItem.

For now, only single-Account AccountGfxItems are ever created. The next 
develoment task is to create multiple-Account Items based on Account 
Display Group settings.

OLD: QList<Account*> _accountList;
NEW: QList<AccountGfxItem*> _accountItemList;

See especially changes in methods:
  void AcctRowGfxItem::removeAccount (Account* acct)
  void AcctRowGfxItem::removeAccountItem (const AccountGfxItem* deadItem)
  void AcctRowGfxItem::clearAccountItems()
  void AcctRowGfxItem::accountGfxItemDeleted (const AccountGfxItem*) // slot

----------------------
SimObjGfxItem.hpp
SimObjGfxItem.cpp
SimulationGfxScene.cpp
WorkspaceGfxScene.cpp
WorkspaceGfxScene.hpp
WorkspaceGfxView.cpp
----------------------

Client changes for change in AcctRowGfxItem and AccountGfxItem architecural
change (vis-a-vis Account Items potentially supporting multiple Accounts
based on Account Group names).

-------------------
RwGraphicsScene.hpp
RwGraphicsScene.cpp
-------------------

Added utilities:
  // Enable/Disable Qt Updates in All RwGrahicsViews
  void setUpdatesEnabledInViews (bool ena);
  bool updatesEnabledInMainView() const; 

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