gnu: twinkle: Update package definition.

* gnu/packages/patches/twinkle-bcg729.patch: New file.
* gnu/packages/telephony.scm (twinkle)[source](patches): Use it.
[build-system]: Change from cmake-build-system to qt-build-system.
[arguments]<#:configure-flags>: Add "-DWITH_ZRTP", "-DWITH_G729".
[arguments]<#:phases>[wrap-executable]: Delete phase.
[native-inputs]: Move readline, file, ucommon, ccrtp, libxml2, speex,
speexdsp, libsndfile, alsa-lib to ...
[inputs]: ... here.  Add bcg729, zrtpcpp, libilbc.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>