apply constraints to names for tasks and task instances in resource configuration

The same rules as for IEC identifiers are applied.
- no non-lating characters, ...
- no IEC keywords
- check for duplicate names in resource configuration

closes #19

{
    "url":"ws://127.0.0.1:8888",
    "realm":"Automation",
    "ID":"wamptest",
    "password":"1234567890",
    "key":"ABCDEFGHIJ"
}