Warning messages significantly affect performance

[ojeda-e]

Unfortunately, the more explicit warning messages introduced in #83 significantly affect the performance of the MembraneCurvature, more particularly in membrane-protein systems, where the messages are overwhelming.
While working on #84, I found a dramatic difference between version 0.0.1 (no explicit messages) and 0.0.2 (explicit messages).
To note, these messages are popping up more often in membrane-protein messages, which is expected, given the fit trans+rot transformation that put lots of atoms out of boundaries.

Possible solutions are:

• Go back to the previous minimal messages in surface.py.
• Set a limit on the number of warning messages that can be triggered.
• Deal with the problem of grid size / wrap coordinates (probably related to NPT fluctuations excluded #47 )

[ojeda-e]

Closing this issue as the solution was implemented in #95

For the record, this solution was tested in a system with 2500 frames and ~18900 atoms.
Performance with explicit warning messages: 57.38 seconds
Performance with WarnOnce: 5.24 seconds.