Added experimental support for shared library dependencies

Added experimental support for shared library dependencies

In fact, I'm not sure, whether dependency of shared libraries is the
real problem. Currently, the problem appears if a shared library depends
on a static library. Then this static library must be created before the
shared one.

This change adds a new link-pseudo-pass, which is called after
library-pass and before binary-pass. This "pseudo" pass doesn't traverse
directories recursively, but instead it processes *.omkvar files
prepared during library-pass. Since the shared libraries are linked
after the static ones, we have no problems with dependencies described
in the previous paragraph.

In future, we will extend this approach to linking of libraries,
binaries and maybe even kernel modules. This allows to save at least
binary-pass and the compilation will be faster.

darcs-hash:20081029091745-f2ef6-daa7a8825364b2bbc40f1f00bfd51dd6676ea4d3.gz