add deep tree tests, some cleanup
fix deep search
another test case and minor cleanup
add test for empty bucket handling
fix empty byte vs nil test problems
Merge pull request #139 from Shopify/moar_c_cursor

More C cursor improvements
Printf's %s and %q do the right thing with []byte; removed string conversion.
Merge pull request #142 from extemporalgenome/Printf-byteslice

Printf's %s and %q already do the right thing with []byte