Resolve between binary and ASCII formats

[sjkelly]

In Meshes there are often binary and ASCII formats for each file type. There doesn't seem to be a way to resolve which one you would like easily. For example file"foo.ply creates a File{:ply}("foo.ply"), but the only dispatchable signatures are File{:binary_ply}, so I cannot use the m_str form.

What should be the behavior here?

[SimonDanisch]

I wrote a prototype to solve this and opened an issue to get some feedback in #13

[timholy]

Closed by #15, see

FileIO.jl/src/registry.jl

Lines 7 to 12 in eb9a416

	add_format(format"PBMText", b"P1", ".pbm")
	add_format(format"PGMText", b"P2", ".pgm")
	add_format(format"PPMText", b"P3", ".ppm")
	add_format(format"PBMBinary", b"P4", ".pbm")
	add_format(format"PGMBinary", b"P5", ".pgm")
	add_format(format"PPMBinary", b"P6", ".ppm")