Integrate gumbo_parser with gtest.

This adds the support to build with gtest submodule through gyp+ninja.

To generate the new ninja files, run:
$ gyp --depth=. gumbo_parser.gyp

To build use the following command line:
$ ninja -C out/Default gumbo_parser_unittests

To run use this command line:
$ out/Default/gump_parser_unittests

Signed-off-by: Thiago Farina <tfarina@chromium.org>
Fix and simplify usage example in readme
Use the shorter include path.

Just gtest/gtest.h also works.

Signed-off-by: Thiago Farina <tfarina@chromium.org>
Merge pull request #54 from craigbarnes/readmefix

Fix usage example in readme
Merge pull request #51 from tfarina/gtest-submodule

Integrate gumbo_parser with gtest.
HtmlParser: Update the list of available tags to the current HTML5 spec.
This adds <template>, <data>, and <main>, renames <command> to <menuitem>,
and moves around <article> and <u> to their current places in the list of
HTML elements.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=51600162
HtmlParser: Add the stack of template insertion modes and some machinery for manipulating that.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=51600185
HtmlParser: Add the IN_TEMPLATE insertion mode and a stub dispatch function
for it.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=51608008
Merge branch 'master' of https://github.com/google/gumbo-parser into moe_writing_branch_from_1fbc93bdf97dde6b07b67abb29a71d779f533dd8
fix some assert bugs
Merge pull request #59 from YuriIvanov/assert_bugs

fix some assert bugs