update for publications.html and stylesheet.css

change dead links such as cosyne/asilomar12.pdf to
http://www.cse.ohio-state.edu/~kannan/cosyne/asilomar12.pdf

created more css styles and deleted many unwanted codes in html
for example i changed <b><font color="#0066cc"> (Best Demo
Award)</font></b> to
<b class="color">(Best Paper Runner-Up)</b>
corrected syntax errors
made Capital codes to lowercase