GSE2 replacing fgets calls to function pointer

* this will allow direct reading of string buffers from python
GSE2: Adding python callback for buffer reading

* also added test on null pointer, could not avoid to the printing of an
  error to stdout
adding decomp_6b_buffer to windows def file
Fix test for zero valued int and float attributes.

- Zero valued int and float attributes are now printed correctly;
- An _eventTypeClassFactory() object is now True even if
  it is only made of zero valued int and float attributes.
add failing test for processing that is passed to scipy done on empty traces
new decorator to skip processing for empty traces
skip (scipy) processing for empty traces (which raises otherwise, usually with something
like IndexError)
Merge remote-tracking branch 'upstream/master' into skip_scipy_for_empty_traces
Merge remote-tracking branch 'upstream/master' into fix_zero_val_attribs
Fix for testcase described in #544.
Test if a trace that fits perfectly into a gap in another trace can be added
modify test, test both methods 0 and 1 for Trace.__add__(), I think they
both should behave the same in this case. Also check that output is a
normal array (no masked array)
fix merging in valid data into masked data.

checking of equality has to be done differently to respect the special
cases involved with masked data.
changelog
credits
Test if dtype remains the same after randomly adding to a trace
convert back to original data's dtype
correct test, now actually fails because of a masked array
after Trace.__add__(): check if we can downgrade to ndarray if we have a
masked_array.
Merge branch 'master' into gse_fct_pointer