Allow libtool symbol files in the objdir

Check if a .sym file is present in the build directory; if so, use it.
Otherwise, fall back to the srcdir copy as we always have.

Change-Id: I57056b8b8300cd302212c313a3a618d5c9f81c31
rx_opaque.h is a thing

Change-Id: I8dcbde837c14050fabeb57fcdb328dae2acc616f
afs_tokens handling for rxgk tokens with pioctl

Change-Id: I1089488bbb26fa56bd6d6b011b2c4b62beaf912d