+ supply a null-terminator to buffer in _nc_viswibuf().
+ fix a sign-extension bug in unget_wch() (report by Mike Gran).
+ minor fixes to error-returns in default function for tputs, as well
as in lib_screen.c
+ modify _nc_panelhook() data to account for a permanent memory leak.
+ fix memory leaks in test/demo_menus
+ fix most warnings from Klocwork tool (report by Larry Zhou).
+ modify configure script CF_XOPEN_SOURCE macro to add case for
"dragonfly" from xterm #236 changes.
+ modify configure script --with-hashed-db to let $LIBS override the
search for the db library (prompted by report by Samson Pierre).
