+ 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).
+ use NCURSES_MOUSE_MASK() in definition of BUTTON_RELEASE(), etc., to
make those work properly with the "--enable-ext-mouse" configuration
(cf: 20050205).
+ improve documentation of build-cc options in INSTALL.
+ work-around a bug in gcc 4.2.4 on AIX, which does not pass the
-static/-dynamic flags properly to linker, causing test/bs to
not link.