Fix a typo
doc: add highlight_html()
doc: add highlight_full()
doc: add highlight_full parameters description
doc: add highlight_html parameters description
nginx: update the latest mainline

1.7.3 ->
1.7.4

This update contains STARTTLS vulnerability fix (CVE-2014-3556)
Merge pull request #186 from naoa/doc-highlight-function

Add document highlight function

Patch by Naoya Murakami. Thanks!!!