new FileHandler nodes

Created by: zeffii

a few straight forward utility nodes, standalone easy to debug.

node name	description
FilePath Selector	spawn a FileSelector dialog
	can
	- output the filename into the tree, or
	- [fullpath, dirname, filename, extension] (user can unpack later).
	- the file as a [string]

or all separate nodes.

• FilePath Selector
• FilePath Decompose
• StringIO From FullFilepath
• Pickle State
• Unpickle State
• pydata picker

i'm starting to need these things.

pydata picker would be something like a really simple switch specifically far simple mesh

| pydata picker |
-----------------
|         verts -
|         edges -
|         faces -
- verts         |
- edges         | 
- faces         |
- index         |
.................