#2 Document ILO performance caveats (909)

[Ron Crisco]

Include in the documentation (beginning near the top of the home page) some words about measurement intrusion in general, ILO's expected measurement intrusion specifically, how to mitigate the intrusion (through judicious decisions about nesting tasks and use of the switch that powers off instrumentation at level n and beyond) and the types of applications that are best suited for ILO use.