Enforce length checking for instance name field

Add the max_length checking for instance name field in Update Instance.
Also changed the max_length value from 80 to 255 in Create Instance
to match the backend's restriction.

Change-Id: I52398a13a545449699a7209db49c06859daa9463
Closes-Bug: #1279590
Pre-select the network when there's only one.

Change-Id: I3eb7fd65188212a17f63d2c38bba179a4c767442
Closes-Bug: #1260227
Fix wrong links to volume detail

instance detail page and stack mapping has wrong links
to volume details (They point to volume snapshot by mistake)

Change-Id: I2c067941034d6a75f5d99fc663fe07515705afe7
Closes-Bug: #1296356
Merge "Enforce length checking for instance name field"
Merge "Fix wrong links to volume detail"
Merge "Pre-select the network when there's only one."