Clean up (and fix) versastack.adminview.js -- Part 2

In versastack.adminview.js:
- Fixed node and link networking so that the graph is working again
- Changed some constants for smoother expansion animation
- Optimized array loops to save array.length value on array
initialization instead of recalculating each iteration as per
guidelines from
www.thinkful.com/learn/javascript-best-practices-2/#Optimize-Loops
- Fixed problems with variable shadowing where var l was used multiple
times
- Replaced all console.log calls to use console.log, console.info,
console.warn, or console.error as appropriate
- Created proper getGroupID(), getLinkID(), and getUID() functions that
can be used consistently
- Rewrote network() to operate top-down by iterating through topologies
then their children, rather than searching for the topologies
corresponding to random children, using new isTopology() and isChild()
functions
- Changed radius() so that topologies are bigger and stand out more
- Fixed issue where links were not centered on node circles
- Bounded x and y coordinates so that no nodes can go outside the
canvas bounds
- Updated section headers

In versastack.model.js:
- Changed child reference to parent id into a direct reference to the
parent node, which simplifies some code