support for creating and sending nested bundles
Update comment for lo_bundle_count().
Add back the lo_bundle_free_messages() function for ABI backward-compatibility.

The function is marked as obsolete, but its symbol must remain exported.
Add a test for a simple case of nested bundles.
Add new bundle functions to export list.
Expose refcount mechanism publicly and use it for freeing.

This allows code to make use of reference counting to keep track of
message and bundle object ownership.  Since lo_message_free(),
lo_bundle_free() and lo_bundle_free_recursive() decrement the counter
and check it before freeing, previous code will work as expected,
however if lo_message_incref() or lo_bundle_incref() are used, actual
free will be deferred until no more references exist.

User code should call always the corresponding lo_message_incref() or
lo_bundle_incref() function when these objects are stored.
Add missing iphlapi library to MSVC project.
Add missing recently-added defines for MSVC config.
Move variable declarations to top of scope for MSVC 2008.
Remove premake4.exe from the repository -- MSVC users should download latest.
Merge branch 'nested_bundles'

Conflicts:
	src/liblo.def.in
A couple of fixes for MSVC from the nested_bundles branch.