C++ FastCGI replacing detectproj on command line

Write CGI replacing the detectproj command line utility - removing unwanted code from: https://github.com/bayertom/detectproj

[x] CGI will accept Georeferencer JSON via HTTP POST - linking with some C++ JSON library
[x] SQLite3 for cache: key, status, result. Status: processing / done / error. Result contains JSON.
[x] First request without existing key in SQLite starts the computing (ideally on background)
[x] If key exists directly return result - or error status
[x] Output - always JSON with all output in one structure (subtrees are GeoJSON)
[x] OGR can be used for DXF to GeoJSON. Or provide own export to GeoJSON (see https://github.com/bayertom/libalgo/blob/master/source/io/DXFExport.hpp).

moravianlibrary / detectproj.mzk.cz