bugfix,init page object's lexed attribute.

the page object's attribute 'lexed' is not correctly inited.so when
use page.lexed to generate the search index file,nothing will be
indexed.
Adapt include in page parsing to works on clientside
Remove dependency for path in parser
Bundle gitbook parser as a client side library
Fix dependency in renderer
Bump version to 1.3.0
Merge branch 'master' of github.com:GitbookIO/gitbook into fork

Conflicts:
	lib/parse/page.js
Merge branch 'fork'

Conflicts:
	lib/parse/page.js