* rawmerge.hpp: generalize/fix condition for consistent timeseries

* introduce propagation of C++ exceptions to Cython/Python
* convert all cout/cerr output to exceptions
* Cython: introduce separate 'do_conversion' => avoid constructor to
trigger conversion

cyt/raw_eater.pyx

@@ -30,6 +30,9 @@ cdef class raweater:
       raise ValueError("'" + str(rawfile) + "' does not exist")
     self.rawit.set_file(rawfile)
 
+  def do_conversion(self):
+      self.rawit.setup_and_conversion()
+
   def validity(self):
     return self.rawit.get_valid()