Incremental commit: blktap2.5

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
blktap2.5 now builds

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Set the XCP_PATH and TAPDISK2 env vars if we detect a parallel install of blktap2.5

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Fix init.d/ffs to cope with parallel installs of blktap2

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
xapi is going to need to know about parallel blktap2 installs too

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Merge branch 'blktap2.5' of github.com:djs55/xenserver-core into storage-motion-fixes

Signed-off-by: David Scott <dave.scott@eu.citrix.com>

Conflicts:
	SPECS/ffs.spec