Also removed the lib-dir merging with sysdep. Updated #include's
accordingly.
Fixed make doc on recent Debian together with moving generated doc into
objdir.
Moved Makefile.in into root dir
Retired all.o and birdlib.a
Linking the final binaries directly from all the .o files.
From now, you can just `make userdocs' in doc, no need to use ugly scripts.
Also, `make progdocs' builds the programmer's documentation in HTML,
LaTeX version to come later.
All documentation is built in obj/doc (resp. doc/ if you do a stand-alone build).
Use `make docs' to make the whole documentation or `make userdocs' resp.
`make progdocs' for user manual resp. developer's guide.
