drinjectlib early injection support

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on November 12, 2011 15:04:00_

this was PR 211367

easiest w/ earliest injection => issue #234 prereq

drinject today doesn't use early_inject (and changing it do so is non-trivial since it will require alt. methods of gathering the relevant addresses, will be easier once we have earliest injection)

coming in late causes problems and we end up telling people to create a parent process and inject from there as a workaround

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=607_