add a README file
replace the COPYING file by a copy of the GPLv3

the individiual source files contain more detailed copyright information.
add the OPM build system
remove trailing whitespace and replace each tabulator character by four spaces
add license headers to the files based on dune-common

it is GPLv2 only, but it comes with a GPL exception, so it should be
fine in the OPM context...
update in-file copyright information according to the git logs
add periodic splines

this was made possible by the fact that we now have a tridiagonal
matrix which supports entries on the lower left and upper right
corners
update Opm::className to use the HAVE_CXA_DEMANGLE macro

this was lost in rebases...
property system: rename print() to printValues()

to make it consistent with the parameter system...
tweaks to the parameter system

- the end of parameter registration is now specific for a type tag
- the meta-data property has been renamed from "ParameterTree" to
  "ParameterMetaData"
- the parameter list is now specific for a type tag (this was/is a bug
  in the current eWoms parameter system!)
- add a function to parse the command line arguments
remove some math routines which do not really make sense

- averaging matrices is a difficult topic and should almost certainly
  not be done entry-by-entry
- the cross product of 3D vectors is quite trivial and the code was
  not generalizable to arbitrary dimensions
matrix/vector classes: big cleanup

quite a bit of bloat could be removed because we don't need to support
GCC 3.3 anymore and (hopefully all) the names have been adapted to
adhere the DUNE styleguide. arguably, these classes are now more DUNE
conformant than DUNE's ;)
change the prerequisites for opm-material
fix a few "comparison between signed and unsigned" warnings