Made spacing and Alignment optional

- Included variables to control spacing and alignment class output.

- Changed the way spacing and alignment classes output, so there are
always silent classes available, but true classes are optional. Best of
both worlds.

- Fixed a bug where headings were outputting negative margins on p tags
at every media query. This was unnecessary.
Cleaned up comments

-Made comments single-line rather than block so they never get output.
This should make debugging cleaner and source maps easier to untangle.