Add csv output option to crucible-verify-raw

[leftwo]

Added an option to crucible-verify-raw that will produce csv output instead of a formatted print.
This will allow easier post processing of the output and ease comparing output from different extent files.

Example output:

BRM42220006 # /tmp/crucible-verify-raw --verbose-csv AEF | head
# file:AEF bs:512 bytes  bc:131072  dirty:true gen:4 flush_number:37009787 ext_ver:2 bonus_sync:21543 defrag:939
file,block,dirty,status,slot_a_result,slot_a_flush_id,slot_a_hash,slot_b_result,slot_b_flush_id,slot_b_hash,selected_slot,data_hash,all_zeros
AEF,0,true,ok,HashMatch,47428,18362918644890996774,SlotHashMismatch,45302,16039251774303925735,true,18362918644890996774,false
AEF,1,true,ok,HashMatch,47428,13247521920287360720,SlotHashMismatch,45302,13200850826928211362,true,13247521920287360720,false
AEF,2,true,ok,HashMatch,47428,10545746106689772998,SlotHashMismatch,45302,12954128592411415433,true,10545746106689772998,false
AEF,3,true,ok,HashMatch,47428,6884446101332089095,SlotHashMismatch,45302,11361899870660325085,true,6884446101332089095,false
AEF,4,true,ok,HashMatch,47428,16980956734254118825,SlotHashMismatch,45302,2419870224295018126,true,16980956734254118825,false
AEF,5,true,ok,HashMatch,47428,16285263515216636595,SlotHashMismatch,45302,17408677481660435227,true,16285263515216636595,false
AEF,6,true,ok,HashMatch,47428,11101626895967727594,SlotHashMismatch,45302,9823985220066489586,true,11101626895967727594,false
AEF,7,true,ok,HashMatch,47428,38394401569940404,SlotHashMismatch,45302,1861286921230100119,true,38394401569940404,false

I'm building some other tools to compare output from crucible-verify-raw, but moving to csv first will make that whole process easier.