Environ v1.1

Minor update of Environ. The new features with respect to Environ 1.0 are:

• Confining potential as additional embedding environment
• Non-linear models of diffuse layers (full Poisson-Boltzmann and modified PB)
• Analytical 1D models of the diffuse layer (Gouy-Chapman-Stern correction of electrostatic potential)

Some minor bugs have been fixed from the previous version, in particular:

• improved minimum image convention for generation of functions: it solves
  incorrect behavior for non-orthorombic cells
• bugfix: laplacian of erfc was not correctly implemented for 1-D and
  2-D systems (calculations with dielectric and 1- or 2-D system boundary
  were affected)
• fixed a bug in dielectric regions when optical permittivity is different from vacuum
• decreased tolerance for check on electronic charge in utils_charges.f90
• fixed a small bug that prevented compilation in environ_init.f90
• modified the local arrays in compute_convolution_fft to avoid
  large automatic arrays written on the stack (segmentation fault on
  Mac with default compilation options, i.e. small stack)