Extended phone regex - see below

Added ^ and $ for start and end so surplus chars cause an error
Extended the numbers allowed in brackets to be 6 so (01224) is allowed
Added the optional space so ext 5555 is allowed as well as ext5555
Made the whole thing case insensitive to allow for EXTENSION
Extended phone regex - see below

Removed ^ and $
Added a-z to the block
Included uppercase letters for x, ext and extension to make it case
insensitive for only this part
Extended phone regex - see below

Changed ([Xx]|[Ee][Xx][Tt]|[Ee][Xx][Tt][Ee][Nn][Ss][Ii][Oo][Nn]) to be a
block: [A-Za-z \:]{1,11}
Added 10 test cases
Merge pull request #82 from u01jmg3/master

Extended phone regex - see below