AbstractBuildForm: parentRecords can now overwritten. Rewrite getActionUrl()....

AbstractBuildForm: parentRecords can now overwritten. Rewrite getActionUrl(). Used new HelperFormElement::buildFormElementId(). Fixed error that textarea elements didn't displayed any value. Removed hidden element for checkboxes. Renamed buildHidden() to buildNativeHidden(). New buildHidden() which stores Hidden value in SIP (instead of transferring via form).
BuiltForm*: moved SIP to POST element (builtNewSep() ).