sidebar refactoring

* Logo altered
* sidebar panels altered
* tweeter timeline added.
logo.png changed
footer dom restructured.
layout.slim structural refactoring
some new js class hacks added.
page template dom refactoring (related to last layout refactoring commit)
cosmetic changes in page layout for sharing icons.
#sidebar restyled & ysgp.css cleaned up
navbar restructured (related with layout changes)