help: load Home.md in aside when not in home,add new markdown syntax

New markdown block "warning"

    ! line1
    ! line2

will be rendered as

   <div class="md_warning"><p>line1</p><p>line2</p></div>

mod/help.php

@@ -1,6 +1,55 @@
 <?php
+define( 'MARKDOWN_PARSER_CLASS',  'ExtendedMarkdown' );
+require_once('library/markdown.php');
+
+class ExtendedMarkdown extends MarkdownExtra_Parser {
+
+	function ExtendedMarkdown() {
+		$this->block_gamut += array(
+			"doBlockWarning" => 45,
+		);
+		parent::MarkdownExtra_Parser();
+	}
+
+	function doBlockWarning($text) {
+		$text = preg_replace_callback('/
+			  (								# Wrap whole match in $1
+				(?>
+				  ^[ ]*![ ]?				# "!" at the start of a line
+					.+\n					# rest of the first line
+				  (.+\n)*					# subsequent consecutive lines
+				  \n*						# blanks
+				)+
+			  )
+			/xm', array(&$this, '_doBlockWarning_callback'), $text);
+
+		return $text;
+	}
+
+	function _doBlockWarning_callback($matches) {
+		$bq = $matches[1];
+		# trim one level of quoting - trim whitespace-only lines
+		$bq = preg_replace('/^[ ]*![ ]?|^[ ]+$/m', '', $bq);
+		$bq = $this->runBlockGamut($bq);  # recurse
+
+		$bq = preg_replace('/^/m', "  ", $bq);
+		# These leading spaces cause problem with <pre> content, 
+		# so we need to fix that:
+//		$bq = preg_replace_callback('{(\s*<pre>.+?</pre>)}sx', array(&$this, '__doBlockWarning_callback2'), $bq);
+
+		return "\n" . $this->hashBlock("<div class='md_warning'>\n$bq\n</div>") . "\n\n";
+	}
+
+	function _doBlockWarning_callback2($matches) {
+		$pre = $matches[1];
+		$pre = preg_replace('/^  /m', '', $pre);
+		return $pre;
+	}
+
+}
 
 if (!function_exists('load_doc_file')) {
+
 	function load_doc_file($s) {
 		global $lang;
 		if (!isset($lang))
@@ -12,26 +61,29 @@ function load_doc_file($s) {
 		if (file_exists($s))
 			return file_get_contents($s);
 		return '';
-}}
+	}
-
 
+}
 
 function help_content(&$a) {
+	
+	
 	nav_set_selected('help');
 
 	global $lang;
 
-	require_once('library/markdown.php');
-
 	$text = '';
 
 	if ($a->argc > 1) {
 		$text = load_doc_file('doc/' . $a->argv[1] . '.md');
 		$a->page['title'] = t('Help:') . ' ' . str_replace('-', ' ', notags($a->argv[1]));
 	}
+	$home = load_doc_file('doc/Home.md');
 	if (!$text) {
-		$text = load_doc_file('doc/Home.md');
+		$text = $home;
 		$a->page['title'] = t('Help');
+	} else {
+		$a->page['aside'] = Markdown($home);
 	}
 
 	if (!strlen($text)) {
@@ -42,6 +94,8 @@ function help_content(&$a) {
 				));
 	}
 	
-	return Markdown($text);
+	$html = Markdown($text);
+	$html = "<style>.md_warning { padding: 1em; border: #ff0000 solid 2px; background-color: #f9a3a3; color: #ffffff;</style>".$html;
+	return $html;
 		
 }