Magnum.h now doesn't include anything except OpenGL headers, thus
changes in Math library don't trigger recompilation of everything, but
only of things really depending on it.
Math constants moved to separate file for similar reasons, de-inlined
some functions to remove the need for some #includes.
Double has 15-17 significant decimal digits precision, extended
the constant to have 15 decimal digits. On the other hand, float has
only 6-9 digits, so there is no need to have more than 9.
Added just-to-be-sure test for sqrt* constants.
Now we can use CORRADE_COMPARE() almost exclusively for comparing
Vector, Matrix instances and all containers from STL. Tests running time
for all 31 tests is now around 0.1 sec instead of two seconds like
before.
Disabled compilation of all benchmarks, because TestSuite cannot handle
them yet.
PKGBUILD from AUR now can shamelessly use check() function without
unnecessary dependencies.