User define system environment variable PY_SITE_PATH, which indicate the site package path, for example, if your python site package is located in C:\Python27\Lib\Site-Packages.
You can make the PY_SITE_PATH variable to this value. (This environment variable is needed because if your keyword is defined by python, it will search into this site package and find it's definition.)
Some function include read file is implemented in sync way, so there may have be blocked if you using goto definition in a very big test case file or a resource file. These functions may be fixed to active async way in later version.
Support goto variable definietion
Support variable scrope analyze
Fix error file suffix support format, for now support .robot file but not .txt file