List of Changes since the Fork 
==============================
In reverse chronological order:

- remove long outdated vcxproj files, support building with cmake and nmake only on Windows
- change update foreign attributes to remove xml:base and add xlink:arcrole to follow whatwg spec
- fixed minor memory leaks
- correctly handle text in form elements
- support for new tags including search and to better follow the latest whatwg parsing spec
- fix for handling </p> and </br> in foreign contexts
- Fix multiple warnings including cast to enum from void pointer
- Re-implement adjust_foreign_attributes() with a gperf hash
- Remove special handling of <menuitem> tag
- Remove special handling of <isindex> tag
- Use realloc(3) instead of malloc(3) in enlarge_vector_if_full()
- Use realloc(3) instead of malloc(3) in maybe_resize_string_buffer()
- Make destroy_node() function non-recursive
- Fix signedness of some format specifiers
- Add maximum element nesting limit
- Remove custom allocator support
- Fix recording of source positions for </form> end tags
- Fix TAGSET_INCLUDES macro to work properly with multiple bit flags
- Re-implement gumbo_normalize_svg_tagname() with a gperf hash
- Replace linear array search in adjust_svg_attributes() with a gperf hash
- Fix duplicate TagSet initializer being ignored in is_special_node()
- Add support for <dialog> tag
- Add missing static qualifiers to hide symbols that shouldn't be extern
- Replace use of locale-dependant ctype.h functions with custom, ASCII-only equiv
- add ability and interface to modify/edit the dom tree after parsing completes
- allow support for xhtml parsing rules controllable via GumboOptions use_xhtml_rules flag
