Made Kotwali Popover Page responsive

Used Bootstrap from CDN to make Kotwali Popover responsive as an
example.
Made all product pages responsive.

Made all product pages fully responsive. Replaced normalize.css with
Bootstrap.min.css (customized version with only responsive grid and
responsive utilities + normalize.css) as it helps achieve
responsiveness + a more fluid layout + contains normalize.css within it.
Merge pull request #69 from sinchan/gh-pages

Made all product pages responsive.