Merging mext_gdal (Japanese drivers)

[Even Rouault]

Email thread started at ​http://lists.osgeo.org/pipermail/osgeojapan-discuss/2015-April/002316.html

Summary of existing findings:

​https://www.dropbox.com/s/4oyhncknavdk2if/gdal110_test.zip contains 2 new GDAL drivers ( FGD: Japanese Fundamental Geographic Data (.xml) & FG-GML : Japanese Fundamental Geographic Data GML(.xml) ) and one OGR driver (FGD).

Ko Nagase mentions in ​http://lists.osgeo.org/pipermail/osgeojapan-discuss/2015-July/002374.html :

There are 2 format types (DLD / GML), 2 recent versions(v3 / v4)
and 2 (or more) data types (5/10m mesh DEM / General vector data .etc)
in FGD data,
and current mext_gdal test version seems to support the following pair.

=====
1. FGD driver: DLD v3 (5/10m mesh DEM)
2. FG-GML driver: GML v3 (5/10m mesh DEM)
3. FGD driver: DLD v3 (General vector data)
=====

What needs to be done for upstream integration:

• add standard X/MIT license text to the new source files (if copyright holders can legally release their code with this license), and appropriate author and copyright information. See other GDAL source files for examples (for example gcore/gdaldataset.cpp)
• add a small HTML page to each driver that describes briefly (in English preferably) the capabilities of the driver. For example pointing to the specification of the format, sample datasets handled by it, etc...
• link those pages from frmts/formats_list.html and ogr/ogrsf_frmts/ogr_formats.html
• add a few tests with freely redistributable small datasets (potentially dummy) in the GDAL python autotest suite ( for GDAL drivers in ​http://svn.osgeo.org/gdal/trunk/autotest/gdrivers . for OGR drivers in ​http://svn.osgeo.org/gdal/trunk/autotest/ogr ). Ko Nagase has provided a few dummy sample datasets in ​https://github.com/sanak/dev-notes/tree/master/datas/fgd