Add IntelliJ files, random.state, results and bin to gitignore
Fix typos in documentation
Refactor SoluteGrid to not use meaningless 'value' variable (Java is garbage collected). Refactor SpatialGrid check for dimensionality to be less confusing
Improve readability by indenting newline
Remove redundant casts, tidy up braces, remove confusing arithmetic
Remove unused variable, minimalTimeStep