'sh' block: now support:
* write-formula: this specify a variable name (aka a *formula*) which will be populated by each line of the output
  of this shell block, the formula is used as a list
* splitter: this specify a splitter for the 'write' argument, by default '\n' is the splitter
* silence: dispell all output to stdout
* amnesia: dispell all output to log files
Upgrade package.json version to 0.0.13