This reverts commit 3d01d36a.

A while back I changed the job sched and work fetch policies to use
REC-based project priority.
The work fetch logic sorts the project list (in CLIENT_STATE::projects)
by descending priority.
This causes two problems:

- If you have a lot of projects, it's hard to find a particular one
  in the event log, e.g. in work_fetch_debug output.
- In the manager's Statistics tab, the selected project can change
  unexpectedly since we identify it by array index,
  and the array order may change.

Solution: sort CLIENT_STATE::projects alphabetically (case insensitive).
In WORK_FETCH, copy this array to a separate array,
that is then sorted by decreasing priority.

Mac installer: fix typos in script which builds BOINC+VBox installer, update VirtualBox version number in script.

Mac installer: name install folders with "x86_64+ instead of "i686" to show that they require a 64-bit capable Mac.  Also code sign the installer package so a lock icon appears in the installer window.

See http://boinc.berkeley.edu/trac/wiki/PrefsUnification

Discrepancies:
- "Consider the computer in use" pref isn't disabled when the two
  "suspend X when computer is in use" prefs are unset.
  Doing this would have greatly complicated things.
- day-of-week prefs aren't implemented

No tooltips yet.

MGR: Fix a mysterious bug which sometimes prevented list headers from being drawn when using generic wxListCtrl.

MGR: Immediately save changes to the registry when sort column or direction is changed, or when user changes which columns are hidden.
We can't immediately save changes to the registry when a user rearranges columns by dragging them, because MS Windows does not send a notification so wxWidgets can't generate an event.