add more asserts on the current code for strokes

this shows that some of the logic may be wrong; track 1 index 1
should have relative 0 as it draws from the file, not silence
compare output .cue with EAC one we add

The EAC one clearly marks the HTOA of one frame as pre-gap, while we
don't yet do that.
reset relative offset on SILENCE/ZERO
Set start and length properly on File
add all EAC cue files for surfer rosa
add doc
add a Source object, but don't use it yet
handle index 00 of track 1 specially
use diffStrings
create index with the correct path by using sources
update tests
now take relative from currentFile
WIP: try to set relative offset correctly based on sources
stop absolutizing
update debug
add/fix debug
add more tests, after calculating expected values for this disc
make sources an object property
also add source for DATAFILE
move some assignments around to be more logical