compile on OS X
Test passed on OS X
Mention OSX support in documentation.
Adapted to Magnum changes.

(what.)
Utility: added test for double-specified arguments in Arguments.
Utility: fixed assert failure on `-long-arguments` parsing in Arguments.
Fixed win32 install dir
Remove totally useless introduction paragraph in building documentation.
We don't need Graphviz for Doxygen docs anymore.

The diagrams were useless anyway.
Mention that native version of Corrade is needed for crosscompiling.
Improve sectioning in building documentation even more.
Merge branch 'master' of https://github.com/xantares/corrade
Utility: fixed trailing whitespace.
Utility: install also test lib to proper location.
Wrap building documentation in namespace for easier referencing.
More building documentation improvements.
TestSuite: exit with proper code on test failure in Emscripten.

std::exit(1) doesn't cause Node.js to exit with non-zero code, thus all
the tests are marked as passed in CTest. To fix the issue,
CORRADE_TEST_MAIN() is calling std::abort() after proper cleanup. This
however causes ugly stack trace to be printed on output. Related to
kripken/emscripten#1371, didn't find better solution yet.
PluginManager: disable dynamic plugins also in Emscripten.

Not sure at all how this would be done. NaCl doesn't need such things
either -- these platforms are just for one-shot deployment, there is no
such thing as system-wide library with additional plugins loaded on
demand by particular applications.
PluginManager: make the test compile also on NaCl newlib and Emscripten.
Move toolchains updating to crosscompiling documentation, clean up.