Update README.md

Added link to commands.rst
removed getnumfriends()
Merge pull request #266 from CharmlessCoin/core

Removed getnumfriends()
Merge pull request #265 from theshadowfog/patch-4

Update README.md
Fixed a build error due to the removal of getnumfriends()
Merge pull request #269 from ragesalmon/master

Fixed a build error due to the removal of getnumfriends()
Merge branch 'master' of git://github.com/irungentoo/ProjectTox-Core into core

Conflicts:
	testing/nTox_win32.c