datapath-windows: event read should not fail when no events

The semantics are read operation are generally to return 0 bytes and
STATUS_SUCCESS when there are no events.

Also, added a fix to assign the PID to the synthetic OVS_MESSAGE formed
for the command validation.

Signed-off-by: Nithin Raju <nithin@vmware.com>
Acked-by: Eitan Eliahu <eliahue@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
datapath-windows: Fix key parsing in Flow.c.

Signed-off-by: Nithin Raju <nithin@vmware.com>
Acked-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
datapath-windows: Fixes in packet created for userspace

A couple of miscellaneous fixes in code that creates a packet for
userspace as well as when we copy the packet to memory specified by
userspace.

Signed-off-by: Nithin Raju <nithin@vmware.com>
Acked-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Build: shared libraries and versioning

These changes cause shared libraries to be built by default. In
particular, lib/libopenvwitch.so, lib/libsflow.so,
ofproto/libofproto.so, and ovsdb/libovsdb.so will be built. Original
behavior of building static objects excusively may be accomplished by
providing the --disable-shared argument to configure.

Additionally, versioning is introduced to each of the libraries objects
paving the way for APIs to be built around them. A detailed comment
outlining the rules for changing a version number is provided in
configure.ac. Note that at this time, the version number is set to
1.0.0, no API is specified yet, and there are no requirements to maintain
any sort of compatibility in any of the libraries.

Signed-off-by: Scott Mann <smann@noironetworks.com>