osdep: add qemu_get_local_state_pathname()
This function returns ${prefix}/var/RELATIVE_PATHNAME on POSIX-y systems,
and <CSIDL_COMMON_APPDATA>/RELATIVE_PATHNAME on Win32.
http://msdn.microsoft.com/en-us/library/
bb762494.aspx
[...] This folder is used for application data that is not user
specific. For example, an application can store a spell-check
dictionary, a database of clip art, or a log file in the
CSIDL_COMMON_APPDATA folder. [...]
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>