I have to commit many things in one big commits.
1. Support 'make install'
2. Better error handle in 'stdio'
3. support 'fgetc','fputc','fungetc' etc.
4. bug fix: cannot handle relative path for command line arguments.
5. support built in startup file, i.e voba.js
6. support initial built in search path in addition to VOBA_PATH
7. output all libraries to one directory, and simplify the test cases, because no need to set VOBA_PATH.
add constant SEEK_END SEEK_CUR and more tests on fseek and ftell. support `rewind`,and `fflush`.
add libfd_module.so. support `open`,`read`,`write` and `close`. all modules use a new pattern.
add fd.int. remove default implementation of template<T> bool Is<T>(Handle<Value>x), link error is better than run-time error. add Is<Value> also.
Add socket. only support Connect, Recv, Send, and Close.
bug fix: to_void_ptr and from_void_ptr, use const_cast to remove constness.
add Shutdown and template<typename T> Local<T> As(Handle<Value> x);
force gc at the end by invoking v8::V8::IdleNotification()
verify that `force gc` in the previous commit working as expected. remove `set_void_pointer`, because no one use it. Add `voba_ctor_base_ptr1` to link a general object pointer with a JS object.
add echo_server.py to test the TCP client.
use low level binding, i.e. bind `socket` and `connect` seperately. leave JS code for higher level abstraction.
add `bind`,`listen`,`accept`. New `test1` has both client and server.
add test2 for ipv4 addr object.
Update README.md, and some simple tests.
Merge branch 'master' of git@github.com:wcy123/voba

Conflicts:
	README.md