Don't use L_COLON in a JavaScript context

posting_buttons.html has a block that adds custom BBCodes to an object. It goes like this:

var help_line = {

	b: '{LA_BBCODE_B_HELP}',

	<!-- BEGIN custom_tags -->

	,cb_{custom_tags.BBCODE_ID}{L_COLON} '{custom_tags.A_BBCODE_HELPLINE}'

	<!-- END custom_tags -->

}

It works fine as long as L_COLON is an ASCII colon U+003A, but if a translator were to define L_COLON as a fullwidth colon U+FF1A it would break the JavaScript. In this example,

should be replaced with a literal ASCII colon.