Merge pull request #108 from pitr-ch/master

Change Type checks form Float to Numeric to work with BigDecimal
Enhanced polling action

 * when resuming, tries first the previous task if present
 * when error occurs while polling, retries several times before
   actually failing
 * it allows to start with short polling intervals and increase that
   later
 * less methods needed to define to actually start using it

For better testing, I've also made the testing logger non-singleton
by default, so that one can set log levels per test. Also, it's
possible better inspect the managed clocks now.
Merge pull request #109 from iNecas/enhanced-polling

Enhanced polling action
Incremental progress calculation

To make the progress calculation much more effective
Merge pull request #110 from iNecas/incremental-progress

Incremental progress calculation
We don't need to save execution plan to update execution time

This should enhance performance by 30% (depending on the complexity of
execution plan).
Merge pull request #111 from iNecas/enhance-executor

We don't need to save execution plan to update execution time
Bump version
Encode binary data in Base64

marshal and then use base64 because not all json libs can correctly escape binary data