Enhancements:
    - Apart from string, value can also be bool, int or float (added get_int and get_float methods)
    - Added write method (show aliased to write)
    - Added set method. Attribute deleted if value set to nothing.
    - Accept IO instead of IOStream for read and write
Merge pull request #6 from tanmaykm/tanmaykm

Added a few enhancements