Renaming static to app folder, adding .hgignore

--HG--
rename : static/css/css.css => app/css/css.css
rename : static/img/bitbucket-64.png => app/img/bitbucket-64.png
rename : static/img/github-64.png => app/img/github-64.png
rename : static/img/gmail-64.png => app/img/gmail-64.png
rename : static/img/linkedin-64.png => app/img/linkedin-64.png