added: module xassert, enhanced assert(3)
added: copyright comments for xassert.[ch]
added: bitmap module.
added: mlog module.
Added elist module
added: bitwise operations (AND, OR, XOR, NOT)
added: module fakeobs
added: stream module (experimental)
 It works for mode "r" and "w" only.
modified: ASSERT() macro changed to xassert()
 due to the name conflict in WIN32.
added: obsutil module.
added: xmalloc module.
modified: BEGIN_C_DECLS macro definition
added: logger for debugging
added: skeleton filter source
added: much more convinent code.
fixed: a possible leak on output_filename.
added: descriptive comments.
added: skeleton filter program using sh.
added: copyright notice
added: obstack_dump() and obstack_belong() for the debugging purpose.
removed: list related functions
fixed: type mismatch on printf()
added: OBSTACK_GETCWD*() to get the current dir.
added: OBSTACK_DUP_GROW*() to copy the growing obj
added: OBSTACK_STR_COPY*() to concat strings.
added: OBSTACK_STR_GROW*() to concat strings.