+sass switch, variable and mixins

adding these features in the sass files so user and set their own styles
and sizes easily. will want to create more mapstyle classes
*minor updates to include more

more attributes to track as suggested by github. project specific files
to be ignored.
+added to repo. unfinished

need further work. will be the demo file for D3 implementation for
dynamic maps.
+d3 related changes

example html and function js file to use D3 to dynamically create a
stately map.
-remove d3 example file.

move to a different branch
-remove d3 related files.

move to another branch
*recompile from scss
Merge pull request #22 from cherihung/dev

Add sass mixin and variables to increase style flexbility