merge library

1. extract the libraries foo and goo.

$ mkdir t
$ cd t
$ ar x ../libfoo.a
$ ar x ../libgoo.a

2. Prepare "Makefile.t"

all:
$(CROSS_COMPILE)g++ -shared -o libbar.so ./t
$(AR) -rcs libbar.a ./t/*.o

3.generate the new lib

$ make -f Makefile.t