Increase test_resources coverage

Get it up from 61% to 88%.

Change-Id: I8bdcd94df63466c96b76b963b9d9a12657c8beaa
Fix inappropriate error message on event-list

"Stack not found" as the error message is incorrect while describing
events of an exist stack with non-existent resource.

We should just use the message that the server sent the client.
Closes-Bug: #1264944

Change-Id: I213474577512e9a56d8c2802e90d76b9c4324c13
Fix help formatting for resource-template

Only the keys, not the functions should be printed,
or the output text is confusing

Closes-Bug: #1265194

Change-Id: Iaeb6e44ce0988d165609d261ab640b82db4a7ea4
Sort resource-type-list output

Change-Id: I98cfe080ae59cc610132cd0bc734447280b2d61b
Fixed typo error OS_IMAGE_URL

OS_IMAGE_URL is not coorect, replaced it with HEAT_URL and did
according changes.

Change-Id: I0c06dfe6c013a358a46eab2ce4e9b7a44d98672d
Wrapped some long lines

Some lines has been wrapped some not. So wrapped the left long lines.

Change-Id: I67b40e580b53cb7dca40112b3a3c112c359893dd
Merge "Sort resource-type-list output"
Merge "Fix help formatting for resource-template"
Merge "Increase test_resources coverage"