Changed two method calls from 'Log' to 'Logf'
Print logs when packets are dropped and -v flag is set
Update window tests

Made WindowTest4-6 slightly more lenient for students who perform
Writes asynchronously and/or who slightly delay the firing of the
epoch timer when the program begins.
Print packet loss debug logs when -v flag is set
Made log messages more clear
Fixed small bug in window tests
Update README.md
Removed .gitignore that is no longer necessary
first version
Merge remote-tracking branch 'upstream/master'

get new things
finished LSP protocol