BEntryOperationEngineBase::Entry: Add node_ref+path c'tor
BEntryOperationEngineBase::Entry: Add debug methods

Add GetPathOrName() and PathOrName() methods which try to get some kind
of usable path or at least a file name for the entry. Useful mainly for
debugging and error reporting cases.
package daemon: Rework error and issue propagation to client

* BDaemonClient: Move inner class BCommitTransactionResult to top level
  and make it public.
* BCommitTransactionResult:
  - Add a whole bunch of specific error code enum values. Such an error
    code is now the primary error, as opposed to before where we would
    mix status_t and enum value errors. There's a systemError property
    of type status_t which may provide additional information, though
    (depending on the primary error type).
  - Remove the errorMessage property. Due to mapping all errors to the
    specific error codes this is no longer necessary. Mixing such a
    message with another error description is also not very helpful when
    it comes to localization (still not supported, though).
  - Add several properties (paths, strings, error codes) that serve as
    arguments to the primary error and are used by FullErrorMessage().
  - Add issues property, a list of instances of new class
    BTransactionIssue. Those describe non-critical issues (e.g. failed
    update of a settings file) that occurred in the process of
    committing the transaction. Those issues should be presented to the
    user by the package management program.
* Exception: Adjust to transport the BCommitTransactionResult
  properties.
* CommitTransactionHandler, FsTransactions, Root, Volume: Adjust to
  BCommitTransactionResult/Exception changes.
* CommitTransactionHandler: Now requires a BCommitTransactionResult to
  which it adds the issues it encounters. The reply BMessage is no
  longer needed, though.
* Volume: Refactor common code from the three methods that use
  CommitTransactionHandler into new method _CommitTransaction.
BPackageManager: Make BCommitTransactionResult available

* BFatalErrorException: Add commitTransactionResult property and
  respective constructor. In case committing the transaction failed,
  BPackageManager throws a BFatalErrorException with the result.
* BFatalErrorException::UserInteractionHandler: Pass
  BCommitTransactionResult to ProgressTransactionCommitted().
pkgman: Print issues from committing the transaction
BPackageManager: Support installing/updating local package files

* The Install() and Update() versions that take a const char* array
  now check whether a string looks like a path to a local package file.
  If so, they use that file instead of interpreting the string as a
  search string.
* Extend the repository hierarchy. There's now a LocalRepository base
  class from which InstalledRepository and the new MiscLocalRepository
  derive. The latter is instantiated once and collects all package files
  specified by path.
BTransactionIssue::ToString(): Fix some strings
pkgman: Update some user messages