EUCA-6583
On close(), needed to get the parent of $el and clear it out, as help
contents are added as a sibling, not as a child of, the dialog content el.
Also found some duplicated IDs in the script templates: instance-help was used
for instances and images, scaling-help was used for scaling groups and launchconfig pages.
Merge pull request #23 from eucalyptus/bugfixes/EUCA-6583

Bugfixes/euca 6583