As a prospective Master's student in Computer Science at the University of Stuttgart, identify the application period for the upcoming winter semester and the general English language proficiency level required for admission. Do not attempt to access external documents like PDFs for specific test scores.
Navigate to the 'Computer Science M.Sc. for prospective students' page on informatik.uni-stuttgart.de. Locate and extract the application period for the winter semester. Identify and extract the general English language proficiency level required for admission.
State the application period for the winter semester as 'November 15 – January 15'. State that the required English language proficiency is 'CEFR level C1'. Do not attempt to open or extract information from any PDF documents.