Stub in MoarVM profile on/off support.
Start writing profiler output.

Template doesn't do any rendering at all yet, just has the JSON blob.
Basic display of routines statistics.
Fix navigation.
Parse JSON string, to avoid Chrome stack overflow.
Show a nice graph to allow timing comparison.
Implement basic call graph browsing.

Also a few other visual tidy-ups.
Show spesh/inline/JIT statistics.
Display of allocation data.
Show GC statistics.
Show routines allocating a particular type.
Profiler new gives microseconds, not nanoseconds.
Optimize JSON construction a little.
Add OSR/Deopt information to profiler output.
Fix deoptOne/deoptAll confusion.
Properly escape backslashes.
Include line numbers and file names.
Implement an overview page.
Show some info about current call graph node.
Annotate what some blocks are for profiler output.