chore(packaging): speed up debian packaging by parallel builds

[mbroadst]

• I have read and agreed to the RethinkDB Contributor License Agreement http://rethinkdb.com/community/cla/

Description

This speeds up debian packaging by adding j flags to the make steps

[AtnNn]

It would be great if RethinkDB was faster to build and package by default.

However forcing -jnproc`` may break for older versions of make (see #475). Make might also warn that

make[1]: warning: -jN forced in submake: disabling jobserver mode.

An alternative might be to pass -jauto to dpkg-buildpackage in mk/packaging.mk. It would be easier for users who don't or can't build with -j to work around the forced parallelism.

[mbroadst]

Ah right! you had mentioned that, I'll check it out

[mbroadst]

hmm bummer:

mbroadst@retinoid:/zdata/rethinkdb (speed-up-debian-packaging *$)# dpkg-buildpackage -jauto
dpkg-buildpackage: unknown option or argument -jauto

Use --help for program usage information.

mbroadst@retinoid:/zdata/rethinkdb (speed-up-debian-packaging *$)# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.4 LTS"

[srh]

Rebased onto next as of c5868f4. No Debians that we support have that old version of make. Having this would have made my life easier.