Setting the DefaultVoice for a voice without a conf file

[Olga Yakovleva]

Hello Didier,

The following problems should now be fixed in master.

> Trying to build from git master gave me this output:
> src/sd_module/list_voices.cpp:29:31: error: operator '==' has no left operand
> #if ((LIBSPEECHD_MAJOR_VERSION==0) && (LIBSPEECHD_MINOR_VERSION<9))

It should now compile without this error.

For now RHVoice assumes Speech Dispatcher 0.8 by default.

You can tell RHVoice what version of Speech Dispatcher it will be used with:

scons spd_version=0.9

> @Olga: I consider providing a RHVoice package for Slint, but am unsure
> which voices I should put in it as I see in voices/README that:
> 
> 1. The Tatar voice can only be used non-commercially.
> 2. The Georgian voice can only be used by individuals for personal use.

Only the Georgian voice is problematic and is now disabled by default. 
The Tatar voice can be redistributed without restrictions as long as 
redistribution doesn't involve charging money for it.

> On the other hand, a complete package is rather heavy (no less than 250M
> uncompressed) so I wouldn't mind stripping it down a bit

There is now an option to include only some of the languages, for Example:

scons languages=english,russian

Olga