Makefile to compile .so in src

Hi Uwe,

1. I don't believe you really need all the flags from above. If so, within a
package, use a Makevars file.

2. R CMD SHLIB QUIC.cpp shoudl do the trick already, perhaps some linker
flags are required for blas that can be specified in the same line, see R
CMD SHLIB --help

Thanks, I think I understand now better.  I was not familiar with
Makevars files (I only dealt with Makefiles before).

I ended up simply using in the Makevars file:

PKG_LIBS = $(LAPACK_LIBS) $(FLIBS) $(BLAS_LIBS)
PKG_CXXFLAGS = -D_LANG_R

which seems to do the job.  I am just slightly uncertain about the $()
notation; in some docs I saw @BLAS_LIBS@ to appear.  So is
$() ok? Is it the right syntax?

Thanks again!
-Matyas