v1.0.5: Add photon distribution analysis and a Burst Analysis node group.

Open a Photon Distribution Analysis window from the graph and fit static one-, two-, and three-state models, or a two-state model that exchanges during the window. Each fit uses one central raw-count window per burst,
with guesses and bounds for the efficiencies and the exchange rate.

The static count likelihood follows photon distribution analysis as introduced by Antonik et al., J. Phys. Chem. B 2006
(https://doi.org/10.1021/jp057257+) and extended to multiple states by Kalinin et al., J. Phys. Chem. B 2008
(https://doi.org/10.1021/jp711942q). The dynamic two-state model follows Kalinin et al., J. Phys. Chem. B 2010
(https://doi.org/10.1021/jp102156t): the fraction of the window spent in each state is the occupation time of a two-state Markov chain.

Move Burst Variance Analysis, Photon Distribution Analysis, and Timetrace Explorer into a Burst Analysis category.