Changes for make libc symbols available

1
Add an '_' to callee functions which can be resolved to external ones.
Since builtin function can't be defined and compiled outside clang,
here define _sync_* in libcHack for passing thru clang, and also
change lib call name of builtin __sync_* to _sync_* in backend.

2
Makefile.inc for involving extra files.
player doesn't need startHack and ShellCreateWorker