Changed the variable used in buildTmplFn from _ to __. (Issue 10)

Compromise choice: a variable name that is unlikely to exist as a global,
or as a field name on data, but is not too long, to keep code size down.

jquery.tmpl.js

@@ -207,15 +207,15 @@
 		tag: {
 			"tmpl": {
 				_default: { $2: "null" },
-				open: "if($notnull_1){_=_.concat($item.nest($1,$2));}"
+				open: "if($notnull_1){__=__.concat($item.nest($1,$2));}"
 				// tmpl target parameter can be of type function, so use $1, not $1a (so not auto detection of functions)
 				// This means that {{tmpl foo}} treats foo as a template (which IS a function). 
 				// Explicit parens can be used if foo is a function that returns a template: {{tmpl foo()}}.
 			},
 			"wrap": {
 				_default: { $2: "null" },
-				open: "$item.calls(_,$1,$2);_=[];",
-				close: "call=$item.calls();_=call._.concat($item.wrap(call,_));"
+				open: "$item.calls(__,$1,$2);__=[];",
+				close: "call=$item.calls();__=call._.concat($item.wrap(call,__));"
 			},
 			"each": {
 				_default: { $2: "$index, $value" },
@@ -232,12 +232,12 @@
 			},
 			"html": {
 				// Unecoded expression evaluation. 
-				open: "if($notnull_1){_.push($1a);}"
+				open: "if($notnull_1){__.push($1a);}"
 			},
 			"=": {
 				// Encoded expression evaluation. Abbreviated form is ${}.
 				_default: { $1: "$data" },
-				open: "if($notnull_1){_.push($.encode($1a));}"
+				open: "if($notnull_1){__.push($.encode($1a));}"
 			},
 			"!": {
 				// Comment tag. Skipped by parser
@@ -314,10 +314,11 @@
 	// Generate a reusable function that will serve to render a template against data
 	function buildTmplFn( markup ) {
 		return new Function("jQuery","$item",
-			"var $=jQuery,call,_=[],$data=$item.data;" +
+			// Use the variable __ to hold a string array while building the compiled template. (See https://github.com/jquery/jquery-tmpl/issues#issue/10).
+			"var $=jQuery,call,__=[],$data=$item.data;" +
 
 			// Introduce the data as local variables using with(){}
-			"with($data){_.push('" +
+			"with($data){__.push('" +
 
 			// Convert the template into pure JavaScript
 			jQuery.trim(markup)
@@ -352,9 +353,9 @@
 							.split( "$1a" ).join( exprAutoFnDetect )
 							.split( "$1" ).join( expr )
 							.split( "$2" ).join( fnargs || def.$2 || "" ) +
-						"_.push('";
+						"__.push('";
 				}) +
-			"');}return _;"
+			"');}return __;"
 		);
 	}
 	function updateWrapped( options, wrapped ) {