VBOX: Be more specific on the reason for the VirtualBox not being ready.  It was a long time between incidents in dealing with a Linux kernel upgrade and the need to recompile the VirtualBox drivers.  Vboxwrapper properly put the task into a waiting mode but the status message in the manager didn't give the right kind of hint as to the problem.
android: Remove the default global prefs override file from the installation process.  The default values are now in the core client.
client: implement support for OpenCL detection of CPUs

Notes:
- The same CPU can have a different cpu_opencl_prop for each of multiple OpenCL platforms.  We send them all to the project server because:
   - Different OpenCL platforms report different values for the same CPU.
   - Some OpenCL CPU apps may work better with certain OpenCL platforms.
- OpenCL has only 64 bits for global_mem_size, so it can report a max of only 4GB; get the CPU RAM size from gstate.hostinfo.m_nbytes.
lib: fix a comment
client: For compatibility with boinc_get_opencl_ids(), don't include CPU when enumerating opencl_dev_index
client: better error handling for OpenCL CPUs
client: better error handling for OpenCL CPUs
WINBUILD: Fix the startup registry key for the 'All Users' install path.
WINBUILLD: Fix skin install location problem
WINBUILD: Fix the bootstrap icon for CE and PTP