add documentation
add documentation
move core.timing -> tools.timing
[core.interfaces] bugfix
[grids.boundaryinfos] fix typo
[parameters.base] fix typo
[algorithms.ei] bugfix
[operators.constructions] bugfix
PEP8 cleanup
remove pylint configuration
add documentation
[core.cache] add 'max_size' argument to DogpileDiskCacheRegion.__init__()
add documentation
[core.interfaces] do not copy class docstring
[core.interfaces] remove whitelist feature from lock()

which has not been used so far. It is probably bad
style to use it anyhow.
[core.interfaces] set _locked directly in ImmutableMeta.__call__()

which prevents two unneccesary function calls.
[core.interfaces] performance tweak

According to %timeit, key.startswith('_') is about three times
slower than key[0] == '_'.
[core.interfaces] use self.init_arguments in with_arguments() and with_()
[core.interfaces] move generate_sid decorator to the playground

It is used nowhere and no one has ever tested it.
[demos] give cg-oned a valid python module name