init: Stop combining actions

In the past, I had thought it didn't make sense to have multiple
Action classes with identical triggers within ActionManager::actions_,
and opted to instead combine these into a single action.  In theory,
it should reduce memory overhead as only one copy of the triggers
needs to be stored.

In practice, this ends up not being a good idea.

Most importantly, given a file with the below three sections in this
same order:

on boot
  setprop a b

on boot && property:true=true
  setprop c d

on boot
  setprop e f

Assuming that property 'true' == 'true', when the `boot` event
happens, the order of the setprop commands will actually be:

setprop a b
setprop e f
setprop c d

instead of the more intuitive order of:

setprop a b
setprop c d
setprop e f

This is a mistake and this CL fixes it.  It also documents this order.

Secondly, with a given 'Action' now spanning multiple files, in order
to keep track of which file a command is run from, the 'Command'
itself needs to store this.  Ironically to the original intention,
this increases total ram usage.  This change now only stores the file
name in each 'Action' instead of each 'Command'.  All in all this is a
negligible trade off of ram usage.

Thirdly, this requires a bunch of extra code and assumptions that
don't help anything else.  In particular it forces to keep property triggers
sorted for easy comparison, which I'm using an std::map for currently,
but that is not the best data structure to contain them.

Lastly, I added the filename and line number to the 'processing
action' LOG(INFO) message.

Test: Boot bullhead, observe above changes
Test: Boot sailfish, observe no change in boot time
Change-Id: I3fbcac4ee677351314e33012c758145be82346e9