Higher-level function for SHA1 hashes in hex encoding

Signed-off-by: Martin Milata <mmilata@redhat.com>
Signed-off-by: Jakub Filak <jfilak@redhat.com>
Implement bthashes

BTHASH is computed from (almost) everything that is contained in a
stacktrace and therefore should be unique (as much as a hash can be).
Related to #66.

Signed-off-by: Martin Milata <mmilata@redhat.com>
Signed-off-by: Jakub Filak <jfilak@redhat.com>
python: bindings for bthash

Signed-off-by: Martin Milata <mmilata@redhat.com>
Signed-off-by: Jakub Filak <jfilak@redhat.com>