Add kynxilrev model.
Rename the package of kynrefrev and kynxilrev models to kynreverb.

* Use new 'KBHlamp80.fits' tables, this is just sort of a formal change to be in
  line with KYN package of models
* Update documentation

* Add direct definition of ionisation of the disc, i.e. instead of indirect
  definition by specifying the density
* Add better definition of Ut(r_ms) in thermal reverberation that is well
  defined for a=1 as well
* Update definition of shifted Ecut

* Add binning and integration in frequencies for lags and amplitudes directly as
  opposed to binning and integration first in real and imaginary parts.
* Add computation of reference lags and amplitudes for total energy band
  excluding the current energy bin of interest for computation of lag/amplitude
  energy dependence.

* Encrease Tmax for computation of light curves for small rout
  due to inner echo and GR effects close to black hole.

* For the lag-frequency dependence, if the Eref1 (par31) parameter is negative,
  the energy reference band is abs(par31) to abs(par32) excluding overlaping
  part with the energy band of interest abs(par29) to abs(par30).