Ticket #82 error retrieving slices: compute left_offset correctly
Ticket #83 modify retrieve_source to only retrieve enough segments to
produce a requested slice
add some debug info to web_public_reader
Ticket #84 incorrect handling of short block
remove unreliable slice check from web_public_reader
Merge branch 'master' into ticket-84-web-public-reader-slice-offset-for-short-block
Ticket #85: check for block offset
Merge branch 'master' into ticket-85-web-public-reader-block-count-error