[[Imported from SVN: r2156]]

Made mark method const, as required to compile the test.
This is really funny. The method mark actually changes the grid but is
const. Yeah, this is where our _nice_ const concept brought us.
Congratulations.

[[Imported from SVN: r2155]]

fixes bug #13

[[Imported from SVN: r2154]]

[[Imported from SVN: r2153]]

[[Imported from SVN: r2152]]

[[Imported from SVN: r2151]]

[[Imported from SVN: r2150]]

[[Imported from SVN: r2149]]

[[Imported from SVN: r2148]]

[[Imported from SVN: r2147]]

[[Imported from SVN: r2146]]

automake more easily

[[Imported from SVN: r2145]]

check" works

[[Imported from SVN: r2144]]

[[Imported from SVN: r2143]]

[[Imported from SVN: r2142]]

[[Imported from SVN: r2141]]

[[Imported from SVN: r2140]]

Also removed warnings.

[[Imported from SVN: r2139]]

[[Imported from SVN: r2138]]

consists of.  The grid wrapper now uses this information and doesn't
recompute everything.
Currently only for the sequential grid.

[[Imported from SVN: r2137]]

[[Imported from SVN: r2136]]

[[Imported from SVN: r2135]]

[[Imported from SVN: r2134]]

[[Imported from SVN: r2133]]

[[Imported from SVN: r2132]]

[[Imported from SVN: r2131]]

[[Imported from SVN: r2130]]

[[Imported from SVN: r2129]]

[[Imported from SVN: r2128]]

[[Imported from SVN: r2127]]

[[Imported from SVN: r2126]]

[[Imported from SVN: r2125]]

[[Imported from SVN: r2124]]

[[Imported from SVN: r2123]]

[[Imported from SVN: r2122]]

[[Imported from SVN: r2121]]

[[Imported from SVN: r2120]]

[[Imported from SVN: r2119]]

[[Imported from SVN: r2118]]

[[Imported from SVN: r2117]]