Adding serialization of objects with arrays (elliotchance#24)

Add tag option for omitting serialization of nil pointer values (elli…

…otchance#22)

Add omitnilptr tag option for omitting encoding of nil pointers. This prevents panicking when attempting encoding struct with nil pointer fields.

Implemented "php" tags for structs (elliotchance#20)

If you marshal or unmarshal from/into a struct, you may want to use go tags for it, instead of staticly using the struct field names just changing the first letter to upper/lower case.

Example:

    type Target struct {
        FirstName string `php:"vorname"`
        LastName string  `php:"nachname"`
    }

This will correctly be filled with the according fields of serialized php object.
Also unmarshaling will not fail if a struct field does not exist, because you may want to skip some fields from php objects.

Fix a ​nested case with associative array (elliotchance#18)

Fixes elliotchance#17

Create LICENSE (elliotchance#14)

fix: escape characters (elliotchance#10)

Some characters are escaped and some are not. There seems to be no rhyme or reason to it.

unmarshall map: multibyte example. Fixes elliotchance#1 (elliotchance#9)

Provided an example test for the specific case in issue elliotchance#1.

unmarshall array: nested associative. Fixes elliotchance#7 (elliotcha…

…nce#8)

This fixes a bug where a nested array might be associative.

do not escape strings (elliotchance#6)

Do not escape strings as PHP does not support escaping in serialized string

Fix panic if MarshalOptions is nil (elliotchance#4)