Fix: Modularize template file copy operation as copyTemplateFile function.
Add: One testcase for copyTemplateFile.
Fix: selecting the correct sphinx-build executable name is different for linux and windows. ``sys`` package is introduced only to figure out the correct executable file name.
Add: two more testcases for copyTemplateFile function. More test cases are needed since only one type of IOError has been tested.
Add: Change in setting window will trigger a force-refresh of the document.
TODO: With more information, this part can be done better.