Cast for safety, minor adjustments

No need to retry, if it's only a single tx
Remove and replace deprecated parts
Proper handling of Exodus transactions

Part 1: transactions are always stored in brackets, otherwise there is
something very wrong - so there is no need, to try this load. Conflicts
with second part.

Part 2: the old part only works, if load at the top fails.

This is necessary to parse and store transactions correctly which are no
generate transactions during Exodus periode, e.g. simple sends.

Tested from scratch without any bootstrap data:

- python msc_bootstrap.py
- python msc_parse.py
- python msc_validate.py
Remove unnecessary files

Files are no longer used, folders are auto-generated.
Merge pull request #49 from dexX7/cleanup

Cleanup