There are 3 ways to specify debug flags.  The debug flag to set to force
multibyte treatment of single byte locales is "m:1".  The format for the
flags is the same for all 3 ways.  The string is of the format:

    flags:bits

where
    
    flags are in the range A-Z, a-z.
    bits are in the range 0-99.

It is possible to combine flags and bits by either specifying a range of
the form:

    [<flag1>]-[<flag2>]

or separating individual flags or ranges by commas.

It is possible to specify bits in the same fashion.  If no value bits
are specified, all 100 bits are set.  If no flags are specfied, none
are set.  Individual entries may be separated by spaces.  A few examples:

    A-z:		sets all debug bits
    A,c:		sets all 'A' and all 'c' debug bits
    -:			sets all bits
    t,a-c:0,1,20-30	sets bits 0, 1, and 20 through 30 for flags
			t, a, b, and c
    a:0 b:1 c:2		sets bit 0 for flag a, bit 1 for flag b, and
			bit 2 for flag c

Flags can be set via either:

    - the -~ option
    - the "*debugLevel" resource
    - the "dttermDebugFlags" environment variable

A few examples:

    dttermDebugFlags=t:1 dtterm
    dtterm -~ t:1
    dtterm -xrm "*dttermLevel: t:1"

If flag v:0 is set, the list of set debug flags will be dumped to
stderr.  The current list of debug flags are rather disorganized.  In
the future, the function DebugF() should be used, and bits > 0 with an
attempt at trying to make some sort of sense.  The following list
sepecfies all the current debug flags.  There is some overlap between
different chunks of code with the same flag.  The current list of debug
flags and bits are:

	B:1	text buffer: verify text buffer before/after line moves
	F:0	focus
	F:1	focus and XmIM setting
	P:0	TermParse.c functions
	T:0	timestamps
	b:0	scrollbar
	c:0	selection
	e:0	exposure
	f:0	font / XFontStruct / XFontSet construction
	f:10	force subprocess fork() failures specified by
		$dttermDebugForkFailures
	i:0	enable not yet implemented function warnings
	i:0	pty input
	i:0	server key press and release
	l:0	linedraw font code
	m:1	force multibyte mode
	m:2	validate multibyte/wide char strings
	n:0	terminal server not run in daemon mode
	o:0	StartOrStopPtyInput()
	o:0	StartOrStopPtyOutput()
	o:0	pty output
	p:0	print error on pty open failures
	p:1	parser: call ParseTrap() on parse of specified char
	p:2	ttyModes parsing
	p:10	pty: allocation: cause allocation failure
	p:20	property change events
	q:0	pending text
	s:0	selection
	s:1	disable COMPOUND_TEXT   selection target
	s:2	disable CS_OF_LOCALE    selection target
	s:3	disable COMPOUND_STRING selection target
	s:4	disable TEXT            selection target
	s:5	disable XA_STRING       selection target
	s:10	signal handler
	t:0	cursor / scrolling code
	t:0	text rendering
	t:1	fill areas before rendering text
	v:0	verbose listing of debug flags
	w:0	terminal window width / height