more tweaks to README.md

Simplified a few blocks and made it easier to read, corrected punctuation and bits here and there.
Merge pull request #209 from pyrobisqit/patch-1

more tweaks to README.md
Fixed something in readme.
Merge pull request #210 from nickodell/master

Show error message instead of "added friendnumber -1"
Added chat windows, and some clean up.
Merge pull request #213 from plutooo/master

Added chat windows, and some clean up.
toxic: Made everything 1000x more userfriendly.
Merge pull request #215 from plutooo/master

toxic: Made everything 1000x more userfriendly.
Backspace key should now work on more terminals in toxic.
remove debugging printf statement
Merge pull request #216 from JFreegman/master

remove debugging printf statement
touch up docs to link to eachother
partially fixed friend add bug (key length test still broken)
Merge branch 'master' of https://github.com/irungentoo/ProjectTox-Core
partially fixed friend add bug (key length test still broken)
small fix
formatting
forgot to print messages
Slight changes
Merge remote-tracking branch 'ProjectTox/master'