Changed property variable names, minor bug fix

Changed the names of property variables in DimDoorsConfig to follow
better variable naming conventions. Removed a duplicate config.save()
call. Noticed that crafting Stabilized Rift Signatures can't be disabled
in the config file, will be adding that option in the next commit.
General note: we need a better way of handling item configuration.
Metaprogramming in Java would be a godsend.
Changed some configuration features

Added flag for disabling whether Stabilized Rift Signatures are
craftable. Autocorrected indentation in some areas. Renamed some
property keys in the config file, but the naming is inconsistent. Will
return soon to make all names consistent. Property values should be
removed from mod_pocketDim and moved to a file, e.g. DDProperties.
Configuration should either be loaded directly into the value variables
or be kept as a separate file, e.g. DDConfiguration. I favor for
integrating configuration reading into the same file as the values and
not declaring Property variables at all.