Update HelloWorld.ino

Adding power connections, just to be thorough
Merge pull request #2162 from ankitdaf/patch-2

Update HelloWorld.ino - Added two lines for documentation
Fix of a bug
Fix of a spelling mistake
Merge pull request #2206 from amulya349/master

Fix of a bug #2199
Merge remote-tracking branch 'arduino/master' into ide-1.5.x