add support for md front matter & open page unlisted

- support page config define in front matter
  - support `title`, which can set HTML title.
    - if `title` is not set, then HTML title will try find page title defined in book.xml
	- if `title` is set but <h1> title not set, it will generated a <h1> title using the value of `title`
  - support `configurations` which can set page level configs here.
- now can open page that has .md file but not defined in book.xml (must in a book defined)
- old.title.gen is not supported yet.

bookshelf.xml

@@ -49,7 +49,7 @@
 		
 		<Page id="main">book.sukazyo.cc:: Rebuild In Progress</Page>
 		<Separator/>
-		<Chapter root="test-collection">
+		<Chapter root="test-collection/">
 			<caption><![CDATA[<i>__test_collection</i>]]></caption>
 			<Page id="enhanced-frontend/test-regex-highlight">RegEX 着色</Page>
 			<Page id="language-parsing/rest">ReST Parser</Page>

morny

@@ -1 +1 @@
-Subproject commit 46d4ebb523afc71a44647a48f4aa7ecd6bf2f7a3
+Subproject commit 8026a49ed642d07c877fa0e984deaf2cf34881b7

ph-bookshelf

@@ -1 +1 @@
-Subproject commit 01ecade69d4246aa587622b55cd49ca1f1185736
+Subproject commit c374b0559ab0e1f4737d9c9e2e0b1036af144ace