Merge pull request #427 from sraue/optional-samba

configure: let select samba support, this patch adds a configure option to en/disable samba support in xbmc. this is usefull if xbmc is not used as a full mediacenter (kiosk systems, embedded systems) where a minimal OS is needed (not using libsmbclient can save around 6MB) or to restrict samba access from xbmc for various reasons. samba support is enabled by default and configure breaks with missing_library if libsmbclient is not found and samba support is not explicity disabled at configure time. on windows samba support is fully enabled

diff --cc configure.in
Simple merge