Correctly escape <> in sequence types
Fix 'addrwess book' typo
Merge pull request #7 from cdumez/addrwess_book

Fix 'addrwess book' typo
Merge pull request #6 from cdumez/fix_sequences

Correctly escape <> in sequence types
Fixed "Ed" status, added link to ED + Github issues, fixed markup

Closes:
https://github.com/sysapps/contacts-manager-api/issues/30
https://github.com/sysapps/contacts-manager-api/issues/29
https://github.com/sysapps/contacts-manager-api/issues/28
https://github.com/sysapps/contacts-manager-api/issues/27
Mark id and lastUpdated as nullable (closes #24)

Also indicate that these contact attributes should be initialized to
null when a contact is created.
Use a String enumeration for Contact gender (closes #21)

Also rename "sex" attribute to "gender" as this is more consistent
with vCard format.
Remove default value for id and lastUpdated attributes.

Those will be documented in the Contact constructor algorithm.
Have remove() method take a contact identifier in argument (closes #9)

The remove() method was previously taking a Contact object in argument,
which is not needed and inconsistent with other specifications.
Use plural form for attributes of array type (closes #20)

Also partially addresses issue #15.
Merge pull request #31 from cdumez/nullable_contact_attributes

Mark id and lastUpdated as nullable (closes #24)
Merge pull request #32 from cdumez/contact_gender

Use a String enumeration for Contact gender (closes #21)
Merge pull request #33 from cdumez/remove_contact_id

Have remove() method take a contact identifier in argument (closes #9)
Merge pull request #35 from cdumez/array_plural

Use plural form for attributes of array type (closes #20)