r/harness: Clear some variables before running lintian

Signed-off-by: Niels Thykier <niels@thykier.net>
Remove some redundant methods/code

Signed-off-by: Niels Thykier <niels@thykier.net>
lintian: Add memory usage information with -ddd and -dddd

Add information about how much memory Lintian spends in L::Collect
objects with -ddd.  At -dddd, breakdown the usage per "field" in the
L::Collect object.

Signed-off-by: Niels Thykier <niels@thykier.net>
L::C::Package: Reuse (intern) some strings in index

Reuse use the string used as key in the index fields instead of making
a(n implicit) copy of it.  The memory saved varies greatly between the
packages (e.g. source:lintian saves about 4% where as the
binary:lintian only saves <1%).

Signed-off-by: Niels Thykier <niels@thykier.net>
L::C::Package: Intern values from file(1)

A trivial interning of the values from file(1) can reduce the memory
overhead of file_info for source:linux by 2.5-3.0 MB (down from ~8MB).

Signed-off-by: Niels Thykier <niels@thykier.net>
L::Collect: Add missing "Needs-Info" header

Signed-off-by: Niels Thykier <niels@thykier.net>
L::C::Package: Fix regression in "hard link"-fixup

Signed-off-by: Niels Thykier <niels@thykier.net>