db: add foreach() command into interface
hashtable: implement foreach callback using v8 vm
js-vm: use TryCatch to catch exceptions using our logger
js-vm: handle correctly malformed js code

Otherwise you will get next error:
  <unknown>:8: Uncaught SyntaxError: Unexpected token (
  #
  # Fatal error in ../src/api.h, line 297
  # CHECK(allow_empty_handle || that != __null) failed
  #
js-vm: redirect console.{log,error}() into our logger
js-vm: move logger prototypes into hashtable to really embed it
jsvm: move all code related to v8 vm into separate module