specdep: Fix tests to match new %dist handling

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Merge pull request #368 from euanh/build-improvements

specdep: Fix tests to match new %dist handling
specdep: Remove libxl-headers from ignore list

Signed-off-by: Euan Harris <euan.harris@citrix.com>
specdep: Import scripts.lib as a proper Python module

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Merge pull request #369 from euanh/build-improvements

Build improvements