Utility function that inserts content instead of <code>${child}</code>
variables on <code>text</code>
@param {String} text Text where child content should be inserted
@param {String} childContent Content to insert
@param {Object} options
@returns {String
function(text, childContent, options) {
			options = _.extend({
				keepVariable: true,
				appendIfNoChild: true
			}, options || {});
			
			var childVariableReplaced = false;
			var utils = require('utils');
			text = utils.replaceVariables(text, function(variable, name, data) {
				var output = variable;
				if (name == 'child') {
					// add correct indentation
					output = utils.padString(childContent, utils.getLinePaddingFromPosition(text, data.start));
					childVariableReplaced = true;
					if (options.keepVariable)
						output += variable;
				}
				
				return output;
			});
			
			if (!childVariableReplaced && options.appendIfNoChild) {
				text += childContent;
			}
			
			return text;
		}