The scratch directory is created under the project folder.

VBOX: Explicitly check the return value if CreateProcess fails while attempting to launch vboxsvc.exe.

VBOX: Add error trap for COM errors raised by the MSVC compiler stubs.  Dump the contents of the error to stderr and halt the wrapper.

VBOX: cut down on some of the noise with spurious 'Status Report' messages when we attempt to launch the VM.

get_Console() is not returning an error, bit the returning IConsole interface is NULL.  Just return an ERR_EXEC instead of crash.

VBOX: Only add the guest additions ISO to the VM if the file has actually been detected on the file system.

Some Linux systems separate the VirtualBox packages so that the guest additions ISO is in a separate package.  We were attempting to add a DVD device for a file that did not exist.

VBOX: If polling for the current VM state fails for any reason, like vboxsvc crashing, do a temp exit for 24 hours.

Before COM, polling for the current state wasn't as critical.  If the poll operation failed, we would try again in one second anyway.

After COM, it is used as a test to see if the communication channel between the wrapper and VirtualBox is still operational.  If not, temp exit and hope things work the next attempt.

Projects may want to handle check-pointing within their own application and skip the disk intensive requirements of a VM snapshot.

VBOX: When attempting to deregister the VM, if we are unable to acquire the session lock, exit the routine with an error. Avoid a crash.

VBOX: Configure a bunch of virtual functions to be purely abstract to avoid a bunch of compiler warnings in gcc

VBOX: Juha pointed out that I took one line of code out to many on a code cleanup pass.  I'm adding it back in.

VBOX: Fix crash if DVD-ROM media had been ejected by some external event.  Technically this shouldn't be happening, but something funky is going on with VirtualBox and we need to handle things that may cause a crash when cleaning up the VM.

VBOX: Make the service install scenario work again.

VBOX: When checking for the existence of a VM registered to a given slot directory, also check for the ISO Contextualization image and cache disk image.  If any type of media is registered to a given slot directory, close it regardless if it is attached to a VM or not.

VBOX: When deregistering a VM, organize the medium list by most recent child first and then release as needed.

VBOX: Introduce the notion of Virtualbox COM namespaces. We currently support VirtualBox 4.2 and VirtualBox 4.3.

VBOX: Do not attempt to restore the current snapshot if the VM hasn't been running long enough to generate one.

VBOX: If something fails during create_vm(), we must release the write lock before deregister_vm() is called. Handle machine and session cleanup at the end if the routine.