Added new methods:  * isnumber, check if argument is a number  * isreal, check if argument is float or integer  * per, percentage difference between two numbers or element-wise Numpy    vectors
Added new methods:
 * isnumber, check if argument is a number
 * isreal, check if argument is float or integer
 * per, percentage difference between two numbers or element-wise Numpy
   vectors

pmacosta/putil,pmacosta/putil