Improvements to YCM dynamic flags. - Fallback to a "companion" item (e.g. header/source) or a nearby item when no flags are found for an item. - Finding a "companion" is also exposed as a standalone script. - Ability to pass extra clang flags, including some from a special file found in the .vimcrosoft directory. - Add support for PCH and other forced-include files. - Add options for short/long args, or forcing forward slashes. - Debugging/troubleshooting options, including dumping a batch file and response file to run clang directly, and the ability to auto-load a solution's last known environment when running in command line.