pdb: add debian init file
pdb: remove pdb from global gitignore
pdb: move gitignore to own directory
pdb: remove internal reference, pointed out from Carsten Bock
pkg/kamailio/deb: new kamailio-extra-modules package.

Adding gzcompress module to extra.

(cherry picked from commit a1de51c55d7bf31c7e9a793ec898073ab158b3cf)
lib/srdb1/schema: added docbook-xml target to Makefile

- generate docbook for dbschema in xml format

(cherry picked from commit 509570a29bbecd6839fcd858c17a20dc04383f23)
doc: updated year and removed unused revhistory from bookinfo.xml

(cherry picked from commit a99e71e609c9f703458ac4304d80c7078f46a129)
xhttp_pi: fix copy/paste error that can lead to a crash when 'order_by_cols' are used
(cherry picked from commit 216faa86af3d6db70fae9186ab2776efc27a5f55)
tls: Add support for Elliptic-Curve Diffie-Hellman Ciphers (ECDH)
tls: Added note to docs about OpenSSL requirement for Elliptic Curve Diffie Hellman (ECDH)