python-lxml: Add version 2.2.8 (initial recipe)

* Imported from oe.dev commit id bc6a94559157e6fcc190a22a259c0f757b8664ae.
* Getting "skipping incompatible libraries" message in compilation log. Fixed that issue by changing --with-xml2-config=${STAGING_BINDIR_NATIVE}/xml2-config to --with-xml2-config=${STAGING_BINDIR_CROSS}/xml2-config.
* Added BBCLASSEXTEND native and nativesdk for native recipe.
* Tested with MACHINE = 'qemuppc'

Signed-off-by: Noor Ahsan <noor_ahsan@mentor.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>