G4 Tiff support

[wiredfool]

G4 tiff read/write support.

Current status: Mostly working.

Works:

• There are tests for file and stringio based image reading
• There are tests for small and large images (there's an internal break at 64k due to a buffer size)
• There's a sanity test for writing that we're getting back what we write out.
• Redistributable images for the tests -- lena and a scan of a US government document.

What's not working:

• A small lena image is failing to read within libtiff. There's a currently disabled test for it. I'm going to dig further, as I don't see what's different about this image that is causing it to fail.

I'd like to get this pulled in if possible to run it through the gauntlet of travis testing on all the other environments that I don't have setup.

[wiredfool]

@aclark4life : I'm seeing errors in the travis testing that I'm not seeing locally -- do you know what the environment is there. Distro/tiff version/etc?

[aclark4life]

Hmmm, I get: NameError: global name 'find_library_file' is not defined

[wiredfool]

There's your find library file issue done.

[aclark4life]

Sweet! Thanks, I'll merge shortly

[someimage]

in those test to read tiff images , can i work under .net? merging images is a way to go. i also can't figure out the reasons to fall.

[wiredfool]

@someimage: I think you have the wrong project.