Merge pull request #36 from gAmUssA/master

fixed callouts warnings
finished History API section for  ch1
added a page for the web workers section ch1
started section on Web Messaging in ch1
Wrote a code sample illustrating Web messaging ch1
minor correction in ch1
added a diagrame and code explanations to messaging in ch1
started writing on offline web apps in ch1
added a diagram and some text to  offline web apps in ch1
added a code sample to save/read data from local storage  in ch1
minor additions in ch1
added a sidebar on HTML5 form input fields in HTML chapter
switched ch2 and ch1 - HTML API is ch2 now
added a couple of pages on IndexedDB in ch2
Updated book.asciidoc
fixed formatting in toc
initial commit of chapter 7