Update and sort .gitignore

Ignore the spec_bin temporary files.  Remove the static presentation
ignores for the website, since they are just linked to now.  Remove
the .rvmrc ignore, since Sequel doesn't use one.

I'm considering removal of the 3 *. entries, but I'll leave them in
for now.

.gitignore

@@ -1,11 +1,10 @@
+*.lock
+*.rbc
+*.swp
+/coverage
+/rdoc
 /sequel-*.gem
+/spec/bin-sequel-*
 /spec/spec_config.rb
-/rdoc
-/coverage
 /www/public/*.html
 /www/public/rdoc*
-/www/public/static/*_presentation
-*.rbc
-*.swp
-*.lock
-.rvmrc