Correct total times in recursions

[mo-mglover]

When routines are called recursively, the total time is incremented in an unsuitable way: at the end of the routine/region. The innermost calls thus increment the total time, as does the next call up, and so on. In this manner, time spent in the innermost calls is added to the total time many times over: one for each call level.

Issue #28 also touches on this, but that's of wider scope. For the moment though, doing one of the following will likely be a small, contained changeset:

1. Sorting out the calling levels, or
2. Just getting the total time correct.

I'm thinking that we store the recursion level in a RegionRecord and increment / decrement as appropriate. We can then either:

1. Take the recursion level into the hash, thus separating out the different recursion levels in the profiler, or
2. Only increment the total time of the recursion level gets back to 0.

[This depends on changes in PR #77 ]