Add busyflag and strorage link to objects.

Initialize default hasher and stevedore.

Give each workerthread an object pointer to be kept populated with
a template object for when lookups miss and need to insert one.

Add libmd to get MD5, (choice of hash-algorithm to be revisited later)

Implement lookup, begin on fetch.



git-svn-id: http://www.varnish-cache.org/svn/trunk@141 d4fa192b-c00b-0410-8231-f00ffab90ce4