BitCCL Integration
This issue contains a list of improvements in the BitCCL area (integrating it):

- [x] Fix security issues with imports still being allowed, for example:
    `template.__globals__['os'].listdir('/')`
- [ ] Start integration process with the Merchants API: extend plugins functionality or move the state from state module to state object or other way that is easier to modify
- [ ] Think of execution policies: store-wide and server-wide, to configure/limit scripts options
- [ ] Integrate into the Merchants API
- [ ] Custom scripts execution policies

Note: BitCCL might be implemented as a plugin (see #242)