Daemonizing Celery on Linux link stale

[Ed McDonagh]

They've changed their URL to: http://docs.celeryproject.org/en/latest/userguide/daemonizing.html

[Ed McDonagh]

Should probably just have a guide instead...

[Ed McDonagh]

Intial celery daemonisation on linux page. Refs #652. [skip ci] docs only

→ <<cset ee32ffb5b39b>>

[Ed McDonagh]

Minor changes, plus adding to changes. Refs #652. [skip ci] docs only

→ <<cset 616d7749f8a9>>

[Ed McDonagh]

Merged in issue652celerydaemonisationlinux (pull request #213)

Fixes #652

→ <<cset bc49e7061516>>

[Ed McDonagh]

Merged in release-0.8.1b2 (pull request #216)

Release 0.8.1b2

Some fixes, lots of docs. Refs #647, #646, #647, #648, #649, #650, #651, #652, #653, #654, #656

→ <<cset d5db3ea11366>>