R: work out dependencies so that loading is quick.

The key is not to import anything from Matrix, unless
it is really needed.
Merge branch 'develop' of github.com:igraph/igraph into develop
R: reworked dependencies again, Import Matrix and use ::.
R: fix authority score test case.

Matrix must be loaded "by hand" now.
Merge branch 'develop' of github.com:igraph/igraph into develop
R: use Matrix:: on tril and triu.

Otherwise they are not visible.
R: fixed biconnected.components() test case.

Apparently, it is not trivial to sort a list of
vectors platform independently in R.
R: fix an example with Matrix.

Need to load explicitly now, because we import it only,
and we don't load it in the code.
barabasi_game uninitialized variable fix.

Crashed R sometimes. The problem was that for empty
vectors igraph_vector_min() return an uninitialized value,
and this was used to check an argument.
Nightly: show all versions.
Nightly: added R OS X binary package type.
Fixed invalid write in graphlets, causing some crashes.
R: make package compile on Windows, add plfit include directory.
Reorganized web page and nightly builds page.
Merging www and nightly.
Fix (harmless) uninitialized variable compiler warning in graphlets.
Updating homepage design. Getting there.
WWW: adding font files, mfizz and an R logo.
WWW: proper excerpts on news page.
WWW: rewrite links to old docs, refer back to sourceforge.