Flavio

This is a quick bug fix release due to an issue affecting the combination of uncertainties of experimental measurements necessary for fitting routines. Thanks to Wolfgang Altmannshofer for indirectly discovering it.

This release brings few minor improvements and bug fixes.

Improvements:
- the charm mass scheme uncertainty is now taken into account in the error estimate of B->Vgamma decays
- several new experimental measurements added

Bugs fixed:
- the sign of the lifetime correction to Bs->phigamma has been corrected (note this is a tiny effect in the SM)
- a bug that affected the computation of likelihoods needed for parameter fits (see d07f7c481b25c16fec223f5d8df4aa0bec72a601)

This is a maintenance release fixing several bugs:
- Several (numerically small) fixes to QCDF corrections in B->Vll decays. Thanks to shulixiaoquan for spotting one of them.
- The plot function `flavio.plots.band_plot` had a missing factor of 2 in the confidence level, so the resulting constraints had been to loose. Thanks to Tom Blake (tblake00) for pointing that out.

There have also been a few minor improvements:
- A faster integration routine and more memoization should speed up prediction of some q²-binned observables by about a factor of 2
- Power corrections to weak annihilation in B->Vll from QCDF have been added.

Finally, the plot function `flavio.plots.smooth_density_histogram` has been renamed to `flavio.plots.smooth_histogram`.

**New processes:**
- Leptonic kaon and pion decays K->lnu and pi->lnu
- Semi-leptonic kaon decays K->pilnu (also known as Kl3 decays)
- Mass-eigenstate rate asymmetry in Bs->phigamma

Special thanks to Jorge Martin Camalich and Martín González-Alonso for help on the kaon decays (see [their recent paper](https://arxiv.org/abs/1605.07114))

**Parametric changes:**
- Meson decay constants, some CKM elements, and the SM kaon bag parameter have been updated to the new [lattice averages by FLAG](https://arxiv.org/abs/1607.00299)
- Small changes in parameters for subleading corrections in B->Vll at low q^2

**Other important changes**
- The sign convention for `S_psiphi` has been flipped to better match the theory literature. Note that with the new convention, the sign of `S_psiphi` is _opposite_ to the sign of phi_s as defined by LHCb experiments. Thanks to Joel Jones-Pérez for noticing this.
- The interface to Flavor Kit has been adapted to match changes in SARAH 4.9.0 released on 2016-07-13. Please to not use flavio 0.10.0+ with older versions of SARAH/Flavor Kit.
- The interface to Flavor Kit now also includes b->snunu operators.

Special thanks to Joel Jones-Pérez, Avelino Vicente, and Florian Staub for improving this interface. More improvements are to come soon.

This release adds a few new processes and fixes several bugs.

**New processes:**
- Time-integrated branching ratio, mixing-induced CP asymmetry, and direct CP asymmetry of the rare radiative Bs->phigamma decay (`BR(Bs->phigamma)`, `S_phigamma`, `ACP(Bs->phigamma)`) (Thanks to Ayan Paul for collaboration)
- Branching ratios of the leptonic charged-current decays B->lnu (`BR(B+>enu)`, `BR(B+>munu)`, `BR(B+>taunu)`)
- The observable `ATIm` in B->Vll decays

**New features:**
- [A function](https://flav-io.github.io/apidoc/flavio/parameters.m.html#flavio.parameters.read_file_values_correlated) to read in custom parameter files with correlated parameters
- [A function](https://flav-io.github.io/apidoc/flavio/io/flha.m.html#flavio.io.flha.read_ckm) to read the values of CKM parameters from an SLHA or FLHA file (thanks to Joel Jones-Perez for the suggestion)

**Bug fixes**
- The total uncertainties of experimental measurements with multiple uncertainties had been combined incorrectly
- The mixing-induced CP asmmyetry in B->K*gamma was not correct in the presence of imaginary contributions to C7'
- There was an error in the lepton flavour violating B->ll' decays

This release fixes a bug that raised an error on import on Python 3.4 (thanks to Joel Jones-Perez for pointing that out!)