Say improvment

I've added a speech generation for situations when user is disconnected from Internet.
For this I've create method in Internet module, that check connection. This method can also be used in other situations when Internet is required.Betty has strong Internet dependency, so such method is very useful I think.
For doing offline text-to-speech I've used spd-say. The quality of speech is bad, but if this feature will be accepted we can use more advanced tools like Festival or others.
The main purpose for spd-say that it is available out of the box.
Also I've got that Ubuntu 14.04 doesn't have mpg123 or afplay in default, so I've added spd-say call if there is no mpg123 or afplay installed.