Initial public commit
Click-able tree now operational
switched to keeping parents, but bugs still present
moved collapse/trim_branch
branch pruning now working
more robust timing structure, cosmetic fixes

renamed stackprof to treeprof
new timing structure now actually works, beginning to add summaries
Added treeprof.summary
visual cues added to `browse` navigation
Broke up `treeprof` into sub functions to facilitate testing
Improved tree manipulation, fixed bugs with pass through functions, started to add tests

Now a test treeprof object available to build tests on.
Now times displayed in thousands
Cleaned up display and added summary with better time units
working to implement tree sorting
got sorting to work
trimming fast branches initial implementation
minor, new tests, now render returns invisibly
small bug fixes, added `as.dt`, added `gctorture`

- Realized that validation for melt_prof was unrealistic since too hard
to figure out what the call stack looks like exactly so simplified it
- `as.dt` allows us to quickly print a `treeprof` as a data table
- added `gctorture`, but it doesn't seem to be as good
modified pass thru collapse to deal with tryCatch with multiple handlers
show time instead of mills, removed dependencies to stringr, plyr

- added time formatting functions
- changed display format a little