CP-9401: Correctly check provision scripts are whitelisted

Using the dirname instead of substring comparison allows us to not have to care
whether we have a '/' or not at the end of our (configurable) path but still
checks that they are actually in the directory that we allow (and not in
another directory that might start with the same string).

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CP-9401: Don't use Fhs for SM directory (+ make it configurable)

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CP-9401: Remove (now-)unused Fhs module

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CP-9401: Remove unused option in globs

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CP-9401: Remove default hardcoded path in genptoken

This now generates the token in the current working directory rather than
putting it in an arbitrary hardcoded place. This can be overridden still (using
-o) which is done by the init script to ensure it ends up where it needs to be.

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CP-9401: Server certificate is non-essential at startup

This is generated by the xapissl scripts which xapi executes and so won't be
there on first start of xapi.

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CP-9401: Don't repeat existence check for executable

This is done as part of the Xcp_service.configure with the
Xapi_globs.Resources.essential_executables list.

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>