Added bass guitar info to guitar page.

- Text copy.
- Kid playing bass image.
Added back to school info to home page.
Added saxophone info to home page.
Added framework for saxophone page.
Rearranged instrument order on home page.
Added saxophone / Removed bass from guitar sub navigation.
Reformatted code on instrument pages.
Javascript validator was missing from most pages, added it where applicable (for contact form).
Updated sub-navigation on each instrument page.
Reformatted all code, primarily to clean up indentation.
Replaced woodwinds link in sub-sub-navigation with saxophone, clarinet, and flute links.