first cut at pass re-implement `ol` command

- `ol clear` and `ol view`
- --age option for specifying a time-based cutoff
  - for view only select object log entries newer than age
  - for clear only clear object olog entries older than age
- still need to
  - remove TDObject and TDObjectLogElementBuilder
  - attach debugger to continuation
implement `attach` menu item in `ol view` for debugging continuations

- actually debugging continuations via RemoteDebuggerLogEntry is
  problematic:
  - DebuggerLogEntry class>>createContinuationFor: breaks when used
    with RemoteDebuggerLogEntry (cannot find compiled method)
  - when the continuation is continued via `value: #debug`, the
    process gets a SIGSEGV (in 3.2)
  - defer til later
- attach works fine
remove TDObjectLog and TDObjectLogElementBuilder as they are no longer used
Issue #39: tweaks to debugger when attached to a continuation

- `debug continuation` menu item in TDObjectLogEntryBrowser attaches
   debugger to the process .. can't step and continue at the moment
- `ol view` command brings up TDObjectLogEntryBrowser