debian: Add a script which builds debian packages

This commit adds a shell script which can be used tu build both source
and binary packages properly. After running it creates source and binary
packages in the current working directory.

Change-Id: I4a2e5ae62e164f5de0ad083ea4653882ec26ed1a
rpm: Add a script which Jenkins uses to build RPMs

This script doesn't create any files, but doesn't fail when building RPM
packages using the same command as in next versions (>= 2.5.4). This
makes Jenkins jobs succeed when building packages for 2.5.2.

Change-Id: I93db65075b1995490428e8d66db8ee628bfa2bc0
debian, rpm: Add packages with debugging symbols

This commit adds generating lizardfs-dbg .deb package (RPMs did already
have this feature) and modifies the build system to include debugging
symbols in the 'Release' build type (to place them in the -dbg
packages).

Change-Id: I858b3be98768c86a69b5b489a3605bf809b8e02a