Nimbus validates topo conf on submission

StormSubmitter logs the actual exception message for invalid topologies,
and it does not log the stack trace twice.
Adds tool tips to the UI to document features.

Upgrades bootstrap CSS
Includes bootstrap twipsy JavaScript for tool tips.
Removes unused UI doc item
Merge branch 'd2r-nimbus-validates-topo-conf-on-submit' of github.com:d2r/incubator-storm