Improve validation - add charset constraints

[mbeckerle]

Various NITF elements are supposed to have specific characters only. E.g,, are not allowed to have any ascii chars but only 0x20-0x7F only for some elements (e.g., excludes all control chars, line-endings, etc.)

These requirements can be expressed using pattern facets, but are missing from the NITF schema.

[mbeckerle]

Additionally, range checks on numbers are not expressed even though they can be captured using facets.

[bradh]

Note that the rules changed between MIL-STD-2500C CN2 and the new Joint BIIF Profile.

[mbeckerle]

Note that the rules changed between MIL-STD-2500C CN2 and the new Joint BIIF Profile.

Do you think it will be needed to handle both, or are the new rules a tightening to where the contraints should have been all along?

[bradh]

The definition of BCS, ECS, etc has not changed. The difference is that ECS-A is now allowed in places where previously only BCS-A was valid.

The basic concept is that a union of NITF and NSIF valid ranges went into JBP. So everything that was valid is still valid, but things that were not valid might now be valid..