Add support for 'true' and false' in value parser.
Add support for 'true' and false' in value parser.

	* src/libuco/uvalue-common.cc(parse): Parse true as 1 and false
	  as 0.

urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi