changed about/version to an array

In order to leave the door open for a future LRS that supports 1.x.x as well as 2.x.x, but without a 2.x.x specification __requiring__ 1.x.x support, making the about/version property an array so that an LRS may list the versions it supports.
[] -> Array, xApi -> xAPI

In response to feedback:
* changed string[] to Array of string
* changed xApi to xAPI
about version

Updated about version to allow indicating support for future and prior versions
Merge pull request #213 from bscSCORM/about

changed about/version to an array
Voided and Signed not props
* moved voided and signed sections out of statement properties list
* re-numbered sections as needed
* no other changes were made in this commit
Merge pull request #226 from bscSCORM/re-org

Voided and Signed not props
Merge pull request #230 from andyjohnson/master

Edits to Section 4.1.3 Verbs
Merge branch 'master' of https://github.com/adlnet/xAPI-Spec
small change to fix error in version prefix
Fixes #232 Added Inverse Functional Identifier as a row in Actor Agent and Group Tables.
Relates to #209 Added required table
Merge pull request #233 from fugu13/versionprefix

Tiny fix for version prefix checking
reformat, removed some redundancy
Merge pull request #1 from bscSCORM/liveaspankaj

minor reformat/de-duplication
#232 minor reformat/de-duplication
Merge pull request #234 from liveaspankaj/master

Fixes #232 Added Inverse Functional Identifier as a row in Actor Agent and Group Tables.   Relates to #209 Added required table
Merge pull request #5 from adlnet/master

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