Hocon Value parse fixes #535 and Hocon ToString fix #534

#### Hocon values was not replaced when assigning a new value to the same path.

    a.b.c = 123
    a.b.c = 456

Result was 123456

#535 

#### Hocon Arrays string representation was incorrectly indented.
Minor cosmetic fix for hocon `ToString`, now indenting array contents properly. 

#534