-new output: full (t0,tau) Fstat map,
  if bands in those params are searched
 -one file per Doppler grid point

Closes #7

Closes #9

transients: user-configurable windows, and some minor things

See merge request GregAshton/PyFstat!7

 -replaces boolean 'transient' flag
 -window type [none,rect,exp]
  for both injections and searches
 -t0, tau bands for gridsearch,
  single-point use (e.g. MCMC) should be unchanged

Previously, a check was done to ensure that all initial positions of the
walkers would yield a non -np.inf prior. This extends this to also check
the likelihood evaluations. The method is also simplified partially

Partially resolves issues in #6

- Adds labels of each stage along the top
- Fixes bug when re-running
- Improves column title of run_setup table

Previously, we used the emcee.PTSampler, but this has been removed from
the master branch of emcee (see discussion here
https://github.com/dfm/emcee/issues/236) and a fork, ptemcee has been
developed. Testing shows this is equivalent (after some changes in the
interface) and perhaps better as it contains the adaptive temperature
ladders developed by Will Vousden (the maintainer of ptemcee)

 This removes the convergence testing ideas previously implemented
 (currently juts commented, but later to be fully removed). These are
clearly not useful without further study, which in itself would be a
better time to develop an implementation.

- Adds back in array method for caching data

- Just run separate 2D and 1D searches for each panel itself
- Some additional clean up of the basic GridSearch method