Need to write XForm for rotated affine transforms

[warmerdam]

We need the ability to write rotated and skewed geotransforms in HFA (.img / .aux) files. This means writing it to look like:

    MapInformation(Eimg_MapInformation) @ 913 + 45 @ 1041
    + projection = 
    +     string = `NAD_1927_UTM_Zone_11N'
    + units = 
    +     string = `meters'

    MapToPixelXForm(Exfr_GenericXFormHeader) @ 498 + 23 @ 626
    + titleList = 
    +     string = `Affine'

      XForm0(Efga_Polynomial) @ 649 + 136 @ 777
      + order = 1
      + numdimtransform = 2
      + numdimpolynomial = 2
      + termcount = 3
      + exponentlist[0] = 0
      + exponentlist[1] = 0
      + exponentlist[2] = 1
      + exponentlist[3] = 0
      + exponentlist[4] = 0
      + exponentlist[5] = 1
      + polycoefmtx[0] = 0.0431012353078778
      + polycoefmtx[1] = 0.00122005255541221
      + polycoefmtx[2] = 0.00284370628720125
      + polycoefmtx[3] = -0.0422836422712025
      + polycoefvector[0] = -33759.9345356599
      + polycoefvector[1] = 157973.934412529

[warmerdam]

This has been implemented in trunk (r13343) and a small test case added for it (r13344).

If the geotransform has non-zero rotation/shear terms it will be written as a MapInforation and XForm node instead of as a MapInfo node.

Part of the implementation was improved support for initializing the size and data type of BASEDATA nodes.

[warmerdam]

Back ported into the 1.4-esri branch and briefly tested in r13345.