Replace uint8_t with char

It's better to avoid using fancy types when they serve no purpose.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
Do not use -Werror by default

Using -Werror prevents temporary debug changes, because it fails on code with
unused functions and variables.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
end2end_test.sh: Remove unused DIGEST calculation

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
Avoid including strerror(errno) in err() call

err() already prints this value anyway.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
end2end_test.sh: Do not count files below depth 2

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
Switch to parity based pack file names

Pack file names like "00000001.pack" can easily lead to confusion when backed
up outside the repository.  Generating a unique file name for every combination
of objects helps this.  The neat thing about parity is that the internal
ordering of the files does not matter, and you can determine whether a pack
file is a combination of two other pack files just by looking at their file
names.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>