Renamed pluggable_transports.[ch] to transports.[ch].

diff --git a/src/or/pluggable_transports.c b/src/or/transports.c
similarity index 100%
rename from src/or/pluggable_transports.c
rename to src/or/transports.c

diff --git a/src/or/pluggable_transports.h b/src/or/transports.h
similarity index 100%
rename from src/or/pluggable_transports.h
rename to src/or/transports.h