Alright! No more mid-commits for today!
What have I done:
1) Added GridViews for checking professor's wish to visit a lesson
2) Finished (I guess) reading input file, fixed (I guess) all minor bugs that appeared
3) Started writing a "write-to-file" aka "save" function
That's all! (I guess)

Signed-off-by: RandomAtHome <random-s_home@list.ru>