#304 bring tclXtNotify.c up to date with Tcl_SetNotifier() change

[Frank H]

The Xt Notifier broke when members were added to
Tcl_NotifierProcs
but InitNotifier() in tclXtNotify.c was not updated to
initialize
them, so some random garbage went into the stub table.

The patch takes care of that as well as a case of a
local variable
hiding a global with the same name, and also clears up
a few
compiler warnings.

[Frank H]

tclXtNotify.c patch