Fixed some indentation.
Added option for not highlighting SQL in heredocs.
Added options related to HTML syntax highlighting.

php_html_in_heredoc controls whether HTML and JavaScript is highlighted inside heredocs
php_html_load controls whether HTML syntax is loaded at all.  This overwrites the php_html_in_strings and
php_html_in_heredoc options to false.
Explained some unexplained options. Cleaned up explanation of folding options.
Moved the JavaScript heredoc up with the HTML one.
Merge pull request #21 from swekaj/option-refactoring

Option refactoring