Keep track of file digests inside RPMs and verify them during load
Merge branch 'hardlinks' into file-digest-verify

Conflicts:
	lib/symboldb/rpm_load.cpp
database::add_file(): Remove unused length variable
Merge branch 'hardlinks' into file-digest-verify

Conflicts:
	lib/symboldb/database.cpp
database::add_file(): Update interface
Merge branch 'hardlinks' into file-digest-verify
rpm_file_info: Add members ino, nlinks
rpm_parse: Extract inode number and link count
database::add_file(): Load the inode number into the database
Merge branch 'hardlinks' into file-digest-verify

Conflicts:
	include/cxxll/rpm_file_info.hpp
	lib/cxxll/rpm_file_info.cpp
	lib/cxxll/rpm_parser.cpp
	lib/symboldb/rpm_load.cpp
Remove TODO item: Hardlink support
Add TODO item: Retry transactions
rpm_load: Check that the contents_id for hardlinked files matches
Move the mtime column from symboldb.file_contents to symboldb.file

This increases deduplication opportunities.