Switched to marked markdown parser.

Fixes #49.
Allow html elements in markdown.

This should enable a workaround for #46. Now the user can put "<br>" as the first line of the section.
Added code to handle a newline as the first character.

This allows for you to make sub-sections in the content of a section. This fixes #46.
Improved fix for #46.

Now supports multiple leading newlines!
Merge pull request #55 from Morgul/feature-ccase-marked

Changed to Marked parser