MGR: fix conflict in Mac builds which was introduced by commit 9dcfb88.
MGR: add #define USE_LIST_CACHE_HINT to determine which platforms should use  on EVT_LIST_CACHE_HINT and which should use EVT_LEFT_DOWN to trigger checking for item selection / deselection in wxListCtrl.  This makes it independent of USE_NATIVE_LISTCONTROL.  This is an improvement on my commit 70639a7.
MGR: Fix error in my commit a862fa5
MGR: Remove debug_level stuff, it should be defined in the setup.h file used by wxWidgets instead.
API/client/vboxwrapper: show notice if need Vbox upgrade

Vboxwrapper detects known buggy versions of Vbox and calls
boinc_temporary_exit().
The "Incompatible version" message appears in the task status
in the BOINC Manager, where some users may never see it.
It needs to appear as a notice, telling the user to upgrade VBox.

To do this, I added an optional argument to boinc_temporary_exit()
saying that the message should be delivered as a notice.
This is conveyed to the client by adding
a line containing "notice" to the temp exit file.
I changed the client and vboxwrapper to use this.
MGR: add #if !USE_LIST_CACHE_HINT t in one more place that should have been included in commit a39f4f9.
VBOX: Fix typo
VBOX: Write output from vboxmonitor (running within the guest VM) to stderr as soon as it is written to the guest VM log.

VirtualBox recreates the guest VM log every time the guest VM is launched.  If the VM is using vboxmonitor to write the status of the job or any potential failures of mounting the shared directory it might have been lost under the old policy.
VBOX: Write the desired checkpoint interval to stderr on startup and every time it changes.
WINBUILD: Update vboxwrappers version to 26080.
VBOX: Report CPU Time instead of elapsed time to boinc_report_app_status()
WINBUILD: Update vboxwrappers version to 26081.
VBOX: Base checkpoints on CPU time instead of elapsed time.
WINBUILD: Update vboxwrapper's version to 26082.
client: delete per-project files when detach project
client: when detach a project, remove the slot directories of its tasks
client: when remove project, delete slot dirs and notice files; leave job log
MGR: disable all wxWidgets debugging support in release builds on Mac (asserts. logging, etc.).
Remove Manager code for writing asserts to log files; it is no longer used since wxASSERT() is now disabled for all platforms.
MGR: fix compiler warning.
Sort filenames in the user file sandbox