[#114] Remove deprecated elements/attributes
[#70] Declare subelements within transaction explicitly

Instead of referencing the ones defined for the activity schema.
This the descriptions to be different and for @percentage to be ommitted
within a transaction.
[#68] Add missing narrative elements

policy-marker/narrative
transaction/provider-org/narrative
transaction/receiver-org/narrative
transaction-date/narrative
[#109] Update version attributes to be of type xsd:string

This is more appropriate now as they are checked against a codelist, and
we want to be explicit that 2.01 and 2.010 are NOT equivalent.
[#116] Change type of linked data attributes to xsd:anyURI
[#117] Align planned-disbursement with budget
[#115] Additional changes from Bill's table

(some changes from the table have been implemented as their own commits
linked to the relevant specific issues)
Move iati-identifier out of common schema

(now it's redefined in activity schema)