ConfigFile: add getID() to LUA interface

Signed-off-by: Jonas Zaddach <zaddach@eurecom.fr>
ConfigFile: range constraints for writeRegisterSymb()

Signed-off-by: Jonas Zaddach <zaddach@eurecom.fr>
ConfigFile: add missing getDouble()

Signed-off-by: Jonas Zaddach <zaddach@eurecom.fr>
ConfigFile: perform concolic injection by default

Default writeRegisterSymb() and writeMemorySymb() to inject
concolic values, by retaining original register/memory content.

Signed-off-by: Luca Bruno <lucab@debian.org>