Replace ad-hoc config file handling with Xcp_service.configure

This is the same as other xapi daemons. It allows each option to
be read from a config file and overriden on the command-line.

Also, extend the default xapi.conf with comments describing all
available options which previously were undocumented.

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Signed-off-by: David Scott <dave.scott@eu.citrix.com>
packaging: allow the path to xapissl to be set in the config file

Signed-off-by: Jonathan Ludlam <jonathan.ludlam@eu.citrix.com>
Signed-off-by: David Scott <dave.scott@eu.citrix.com>
packaging: Move pool role path and pool secret path into xapi_globs

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Signed-off-by: David Scott <dave.scott@eu.citrix.com>
packaging: allow the path to udhcpd to be specified

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Remove config_shared (unused module)

Signed-off-by: David Scott <dave.scott@citrix.com>
xapi.spec.in: hard-code /etc/xensource as we do elsewhere

We will eventually replace this spec file with one from the buildroot.
In the meantime we follow the existing convention.

Signed-off-by: David Scott <dave.scott@citrix.com>
Minor build fix following an upstream change

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Merge pull request #1668 from djs55/from-xenserver-core-xcp-services

Replace ad-hoc config file handling with Xcp_service.configure