Add doc for matfaust.lazylinop.eye + fix of matfaust.lazylinop brief desc.

wrapper/matlab/+matfaust/+lazylinop/eye.m

+%> @package matfaust.lazylinop @brief The matfaust module for lazy linear operators.
+%=============================================================
+%> @brief Returns the LazyLinearOp for eye.
+%>
+%> @param m: (int) the number of rows.
+%> @param n: (int, optional) the number of columns.
+%> @param k: (int, optional) diagonal to place ones on. Default is 0 (main diagonal). Negative integer for a diagonal below the main diagonal, strictly positive integer for a diagonal above.
+%> @param 'dtype', str: data type of the LazyLinearOp ('double', 'single', 'complex').
+%>
+%>
+%=============================================================
 function EL = eye(m, varargin)
 	import matfaust.lazylinop.*
 	p = inputParser;

wrapper/python/pyfaust/lazylinop.py

@@ -1085,6 +1085,8 @@ def eye(m, n=None, k=0, dtype='float'):
         m: (int) Number of rows of the LazyLinearOp.
         n: (int) Number of columns. Default is m.
         k: (int) Diagonal to place ones on. Default is 0 (main diagonal).
+        Negative integer for a diagonal below the main diagonal, strictly
+        positive integer for a diagonal above.
         dtype: (str) data type of the LazyLinearOp.
 
     <b>See also:</b> scipy.sparse.eye.