doc of FixedVarDescr
get rid of data_specs field that PL created but did not support
documented SumOfCosts.get_fixed_var_descr
PL evidently copy-pasted merge and then wrote a broken unsupported
version of it. Reverted to a call to merge.
updated documentation of the Pascalocalypse
improved doc formatting
doc and made CompositeSpace call superclass
remove use of unsupported FixedVarDescrs.data_specs
make Conv2DSpace call the base class
automated whitespace fix + spelling fix
remove commented code that PL stealthily murdered some time ago
clean up unit test that PL made messy and dependent on unsupported field
better error message
Merge pull request #594 from goodfeli/fixed_var_descr

Partial repair of FixedVarDescr