MT#7335 Update Debian packaging regarding Python for jessie

According to https://wiki.debian.org/Python/TransitionToDHPython2
MT#7335 Fix incompatibility with glib version from Debian/jessie

Fails with:

| In file included from ../../include/clplumbing/cl_uuid.h:19:0,
| from cl_uuid.c:56:
| /usr/include/glib-2.0/glib/gtypes.h:29:2: error: #error "Only <glib.h> can be included directly."
MT#7335 Fix socket.h/ucast.c conflict when compiling for Debian/jessie

Fails when compiling against Debian/jessie with:

| ucast.c: In function 'HB_make_send_sock':
| ucast.c:466:6: error: conflicting types for 'i'
|   int i = 1;
|       ^

As noted in #713662 "in the current /usr/include/asm-generic/socket.h both macros are defined",
patch also taken from https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=713662
MT#7335 Run wrap-and-sort on Debian packaging

The current heartbeat package in Debian (1:3.0.5+hg12629-1)
looks completely different anyway, so there's no point in
keeping it backwards compatible any longer, instead let's make
it more practicable for developers.

Fixed encoding problems with debian/copyright while at it.