datablock :: avoid reading beyond EOF

Resolves #29

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
add test12 to check #29, reading beyond eof

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
test13 :: all blocks are found but file is damaged

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
reduce number of loops by UpdateVerificationResults

Only run UpdateVerificationResults at the end of a files subset check.
Now it was run on every file checked which is not nescessary.

This could possibly speed up some things.

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
test14 :: remove 1 byte at the beginning of a file

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
set and use original filesize in datablock

if we know the original filesize we can detect problems better,
for example 1 byte missing at the end of a datafile could go undetected
very easy. now that is solved.

this resolves #30

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
after fixing #30 add test13 and 14

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
bump 0.6.7

Signed-off-by: BlackEagle <ike.devolder@gmail.com>