Add ToStringMapBool

ToStringMapBool is useful for a map of flags in a configuration file.
Updated to return bool false only for zero
Updated README, it was describing the wrong return type
Merge pull request #4 from bjornerik/tostringmapbool
Merge pull request #5 from txgruppi/master

Updated to return bool false only for zero
Merge pull request #6 from txgruppi/readme-update

Updated README, it was describing the wrong return type
Add support for HTML to String
Defaulted .ToStringE to use reflection to find a stringer element
Revert "Defaulted .ToStringE to use reflection to find a stringer element"

This reverts commit c0388c79a01c8c97f1914580913631e422689df2.

An attempt to debug Hugo build issues.