build: fixed modules depends

fixes #19

modules/kmemcached/kmemcached.mk

 kmemcached_CFLAGS := -fvisibility=hidden -fPIC
 kmemcached_SOURCES := modules/kmemcached/kmemcached.c modules/kmemcached/namedb_memcached.c
+kmemcached_DEPEND := $(libkres)
 kmemcached_LIBS := $(libkres_TARGET) $(libkres_LIBS) $(libmemcached_LIBS)
 $(call make_c_module,kmemcached)

modules/redis/redis.mk

 redis_CFLAGS := -fvisibility=hidden -fPIC
 redis_SOURCES := modules/redis/redis.c modules/redis/namedb_redis.c
+redis_DEPEND := $(libkres)
 redis_LIBS := $(libkres_TARGET) $(libkres_LIBS) $(hiredis_LIBS) $(libuv_LIBS)
 $(call make_c_module,redis)

modules/stats/stats.mk

 stats_CFLAGS := -fvisibility=hidden -fPIC
 stats_SOURCES := modules/stats/stats.c
-stats_DEPEND := $(libkres) $(contrib)
+stats_DEPEND := $(libkres)
 stats_LIBS := $(contrib_TARGET) $(libkres_TARGET) $(libkres_LIBS)
 $(call make_c_module,stats)