Consistency checks for configuration

[chillenzer]

We should add consistency checks for the configuration of the allocator. As already fixed in #247, similar fixes are on their way for the tests directory. Consistency checks could be: Can we fit at least one element of each hierarchy level into the one above? E.g., is the given heap size big enough to accommodate for at least one accessblocksize? Does at least one region fit into accessblocksize? Etc.