done in sipvoiplink, alsalayer

Removal of libs/libiax2 from the git repo.
Use instead sflphone-iax2-dev from the sflphone repo.
Other debian package available: sflphone-iax2

To execute the program you only need sflphone-iax2; to compile it, you need the headers in sflphone-iax2-dev

Change the name of the libiax library

Remove script src/sflphone.in

ILBC support is not really functionnal so the false the flag BUILD_ILBC is nerver defined

If you disable gsm support, you dont need libgsm1-dev anymore

Website update + clean build system

SFLPhone will now compile and run without libiax, but I can't carantee it won't crash.