Refactor btsnoop and stack config into modules

Moves stack config out of the combined bte_config, and into
its own module.

Makes btsnoop more self sufficient and removes uneccessary
levels of indirection.

Refactor logging slightly into a (temporary) module to disassociate
from the direct calls from config. Eliminates some useless stuff in
the module as well.
diff --git a/main/Android.mk b/main/Android.mk
index b25d828..da5365c 100644
--- a/main/Android.mk
+++ b/main/Android.mk
@@ -15,7 +15,8 @@
 	bte_main.c \
 	bte_init.c \
 	bte_logmsg.c \
-	bte_conf.c
+	bte_conf.c \
+	stack_config.c
 
 # BTIF
 LOCAL_SRC_FILES += \